apiVersion: v1
kind: ConfigMap
metadata:
  name: cassandra-configmap-v2
data:

  pre_run.sh: |-
    echo "** this is a pre-scrip for run.sh that can be edit with configmap"
    #test "$(hostname)" == 'cassandra-demo-dc1-rack2-0' && echo "update param" && sed -i 's/windows_timer_interval: 1/windows_timer_interval: 2/' /etc/cassandra/cassandra.yaml
    #test "$(hostname)" == 'cassandra-demo-dc1-rack3-0' && echo "-Dcassandra.replace_address_first_boot=172.31.183.209" > /etc/cassandra/jvm.options

    #test "$(hostname)" == 'cassandra-demo-dc2-rack1-0' && echo "-Dcassandra.override_decommission=true" > /etc/cassandra/jvm.options
    
    echo "** end of pre_run.sh script, continue with run.sh"
  cassandra.yaml: |
    # Cassandra storage config YAML From CONFIGMAP
    
    # NOTE:
    #   See http://wiki.apache.org/cassandra/StorageConfiguration for
    #   full explanations of configuration directives
    # /NOTE
    
    #This var is computed by the Docker Image (see run.sh)
    cluster_name: 'Test Cluster'
    
    # This defines the number of tokens randomly assigned to this node on the ring
    # The more tokens, relative to other nodes, the larger the proportion of data
    # that this node will store. You probably want all nodes to have the same number
    # of tokens assuming they have equal hardware capability.
    #
    # If you leave this unspecified, Cassandra will use the default of 1 token for legacy compatibility,
    # and will use the initial_token as described below.
    #
    # Specifying initial_token will override this setting on the node's initial start,
    # on subsequent starts, this setting will apply even if initial token is set.
    #
    # If you already have a cluster with 1 token per node, and wish to migrate to
    # multiple tokens per node, see http://wiki.apache.org/cassandra/Operations
    num_tokens: 256
    
    # Triggers automatic allocation of num_tokens tokens for this node. The allocation
    # algorithm attempts to choose tokens in a way that optimizes replicated load over
    # the nodes in the datacenter for the replication strategy used by the specified
    # keyspace.
    #
    # The load assigned to each node will be close to proportional to its number of
    # vnodes.
    #
    # Only supported with the Murmur3Partitioner.
    # allocate_tokens_for_keyspace: KEYSPACE
    
    # initial_token allows you to specify tokens manually.  While you can use # it with
    # vnodes (num_tokens > 1, above) -- in which case you should provide a
    # comma-separated list -- it's primarily used when adding nodes # to legacy clusters
    # that do not have vnodes enabled.
    # initial_token:
    
    # See http://wiki.apache.org/cassandra/HintedHandoff
    # May either be "true" or "false" to enable globally
    hinted_handoff_enabled: true
    # When hinted_handoff_enabled is true, a black list of data centers that will not
    # perform hinted handoff
    # hinted_handoff_disabled_datacenters:
    #    - DC1
    #    - DC2
    # this defines the maximum amount of time a dead host will have hints
    # generated.  After it has been dead this long, new hints for it will not be
    # created until it has been seen alive and gone down again.
    max_hint_window_in_ms: 10800000 # 3 hours
    
    # Maximum throttle in KBs per second, per delivery thread.  This will be
    # reduced proportionally to the number of nodes in the cluster.  (If there
    # are two nodes in the cluster, each delivery thread will use the maximum
    # rate; if there are three, each will throttle to half of the maximum,
    # since we expect two nodes to be delivering hints simultaneously.)
    hinted_handoff_throttle_in_kb: 1024
    
    # Number of threads with which to deliver hints;
    # Consider increasing this number when you have multi-dc deployments, since
    # cross-dc handoff tends to be slower
    max_hints_delivery_threads: 2
    
    # Directory where Cassandra should store hints.
    # If not set, the default directory is $CASSANDRA_HOME/data/hints.
    hints_directory: /var/lib/cassandra/hints
    
    # How often hints should be flushed from the internal buffers to disk.
    # Will *not* trigger fsync.
    hints_flush_period_in_ms: 10000
    
    # Maximum size for a single hints file, in megabytes.
    max_hints_file_size_in_mb: 128
    
    # Compression to apply to the hint files. If omitted, hints files
    # will be written uncompressed. LZ4, Snappy, and Deflate compressors
    # are supported.
    #hints_compression:
    #   - class_name: LZ4Compressor
    #     parameters:
    #         -
    
    # Maximum throttle in KBs per second, total. This will be
    # reduced proportionally to the number of nodes in the cluster.
    batchlog_replay_throttle_in_kb: 1024
    
    # Authentication backend, implementing IAuthenticator; used to identify users
    # Out of the box, Cassandra provides org.apache.cassandra.auth.{AllowAllAuthenticator,
    # PasswordAuthenticator}.
    #
    # - AllowAllAuthenticator performs no checks - set it to disable authentication.
    # - PasswordAuthenticator relies on username/password pairs to authenticate
    #   users. It keeps usernames and hashed passwords in system_auth.credentials table.
    #   Please increase system_auth keyspace replication factor if you use this authenticator.
    #   If using PasswordAuthenticator, CassandraRoleManager must also be used (see below)
    authenticator: PasswordAuthenticator
    
    # Authorization backend, implementing IAuthorizer; used to limit access/provide permissions
    # Out of the box, Cassandra provides org.apache.cassandra.auth.{AllowAllAuthorizer,
    # CassandraAuthorizer}.
    #
    # - AllowAllAuthorizer allows any action to any user - set it to disable authorization.
    # - CassandraAuthorizer stores permissions in system_auth.permissions table. Please
    #   increase system_auth keyspace replication factor if you use this authorizer.
    authorizer: CassandraAuthorizer
    
    # Part of the Authentication & Authorization backend, implementing IRoleManager; used
    # to maintain grants and memberships between roles.
    # Out of the box, Cassandra provides org.apache.cassandra.auth.CassandraRoleManager,
    # which stores role information in the system_auth keyspace. Most functions of the
    # IRoleManager require an authenticated login, so unless the configured IAuthenticator
    # actually implements authentication, most of this functionality will be unavailable.
    #
    # - CassandraRoleManager stores role data in the system_auth keyspace. Please
    #   increase system_auth keyspace replication factor if you use this role manager.
    role_manager: CassandraRoleManager
    
    # Validity period for roles cache (fetching granted roles can be an expensive
    # operation depending on the role manager, CassandraRoleManager is one example)
    # Granted roles are cached for authenticated sessions in AuthenticatedUser and
    # after the period specified here, become eligible for (async) reload.
    # Defaults to 2000, set to 0 to disable caching entirely.
    # Will be disabled automatically for AllowAllAuthenticator.
    roles_validity_in_ms: 2000
    
    # Refresh interval for roles cache (if enabled).
    # After this interval, cache entries become eligible for refresh. Upon next
    # access, an async reload is scheduled and the old value returned until it
    # completes. If roles_validity_in_ms is non-zero, then this must be
    # also.
    # Defaults to the same value as roles_validity_in_ms.
    # roles_update_interval_in_ms: 2000
    
    # Validity period for permissions cache (fetching permissions can be an
    # expensive operation depending on the authorizer, CassandraAuthorizer is
    # one example). Defaults to 2000, set to 0 to disable.
    # Will be disabled automatically for AllowAllAuthorizer.
    permissions_validity_in_ms: 2000
    
    # Refresh interval for permissions cache (if enabled).
    # After this interval, cache entries become eligible for refresh. Upon next
    # access, an async reload is scheduled and the old value returned until it
    # completes. If permissions_validity_in_ms is non-zero, then this must be
    # also.
    # Defaults to the same value as permissions_validity_in_ms.
    # permissions_update_interval_in_ms: 2000
    
    # Validity period for credentials cache. This cache is tightly coupled to
    # the provided PasswordAuthenticator implementation of IAuthenticator. If
    # another IAuthenticator implementation is configured, this cache will not
    # be automatically used and so the following settings will have no effect.
    # Please note, credentials are cached in their encrypted form, so while
    # activating this cache may reduce the number of queries made to the
    # underlying table, it may not  bring a significant reduction in the
    # latency of individual authentication attempts.
    # Defaults to 2000, set to 0 to disable credentials caching.
    credentials_validity_in_ms: 2000
    
    # Refresh interval for credentials cache (if enabled).
    # After this interval, cache entries become eligible for refresh. Upon next
    # access, an async reload is scheduled and the old value returned until it
    # completes. If credentials_validity_in_ms is non-zero, then this must be
    # also.
    # Defaults to the same value as credentials_validity_in_ms.
    # credentials_update_interval_in_ms: 2000
    
    # The partitioner is responsible for distributing groups of rows (by
    # partition key) across nodes in the cluster.  You should leave this
    # alone for new clusters.  The partitioner can NOT be changed without
    # reloading all data, so when upgrading you should set this to the
    # same partitioner you were already using.
    #
    # Besides Murmur3Partitioner, partitioners included for backwards
    # compatibility include RandomPartitioner, ByteOrderedPartitioner, and
    # OrderPreservingPartitioner.
    #
    partitioner: org.apache.cassandra.dht.Murmur3Partitioner
    
    # Directories where Cassandra should store data on disk.  Cassandra
    # will spread data evenly across them, subject to the granularity of
    # the configured compaction strategy.
    # If not set, the default directory is $CASSANDRA_HOME/data/data.
    data_file_directories:
        - /var/lib/cassandra/data
    
    # commit log.  when running on magnetic HDD, this should be a
    # separate spindle than the data directories.
    # If not set, the default directory is $CASSANDRA_HOME/data/commitlog.
    commitlog_directory: /var/lib/cassandra/commitlog
    
    # policy for data disk failures:
    # die: shut down gossip and client transports and kill the JVM for any fs errors or
    #      single-sstable errors, so the node can be replaced.
    # stop_paranoid: shut down gossip and client transports even for single-sstable errors,
    #                kill the JVM for errors during startup.
    # stop: shut down gossip and client transports, leaving the node effectively dead, but
    #       can still be inspected via JMX, kill the JVM for errors during startup.
    # best_effort: stop using the failed disk and respond to requests based on
    #              remaining available sstables.  This means you WILL see obsolete
    #              data at CL.ONE!
    # ignore: ignore fatal errors and let requests fail, as in pre-1.2 Cassandra
    disk_failure_policy: stop
    
    # policy for commit disk failures:
    # die: shut down gossip and Thrift and kill the JVM, so the node can be replaced.
    # stop: shut down gossip and Thrift, leaving the node effectively dead, but
    #       can still be inspected via JMX.
    # stop_commit: shutdown the commit log, letting writes collect but
    #              continuing to service reads, as in pre-2.0.5 Cassandra
    # ignore: ignore fatal errors and let the batches fail
    commit_failure_policy: stop
    
    # Maximum size of the key cache in memory.
    #
    # Each key cache hit saves 1 seek and each row cache hit saves 2 seeks at the
    # minimum, sometimes more. The key cache is fairly tiny for the amount of
    # time it saves, so it's worthwhile to use it at large numbers.
    # The row cache saves even more time, but must contain the entire row,
    # so it is extremely space-intensive. It's best to only use the
    # row cache if you have hot rows or static rows.
    #
    # NOTE: if you reduce the size, you may not get you hottest keys loaded on startup.
    #
    # Default value is empty to make it "auto" (min(5% of Heap (in MB), 100MB)). Set to 0 to disable key cache.
    key_cache_size_in_mb:
    
    # Duration in seconds after which Cassandra should
    # save the key cache. Caches are saved to saved_caches_directory as
    # specified in this configuration file.
    #
    # Saved caches greatly improve cold-start speeds, and is relatively cheap in
    # terms of I/O for the key cache. Row cache saving is much more expensive and
    # has limited use.
    #
    # Default is 14400 or 4 hours.
    key_cache_save_period: 14400
    
    # Number of keys from the key cache to save
    # Disabled by default, meaning all keys are going to be saved
    # key_cache_keys_to_save: 100
    
    # Row cache implementation class name.
    # Available implementations:
    #   org.apache.cassandra.cache.OHCProvider                Fully off-heap row cache implementation (default).
    #   org.apache.cassandra.cache.SerializingCacheProvider   This is the row cache implementation availabile
    #                                                         in previous releases of Cassandra.
    # row_cache_class_name: org.apache.cassandra.cache.OHCProvider
    
    # Maximum size of the row cache in memory.
    # Please note that OHC cache implementation requires some additional off-heap memory to manage
    # the map structures and some in-flight memory during operations before/after cache entries can be
    # accounted against the cache capacity. This overhead is usually small compared to the whole capacity.
    # Do not specify more memory that the system can afford in the worst usual situation and leave some
    # headroom for OS block level cache. Do never allow your system to swap.
    #
    # Default value is 0, to disable row caching.
    row_cache_size_in_mb: 0
    
    # Duration in seconds after which Cassandra should save the row cache.
    # Caches are saved to saved_caches_directory as specified in this configuration file.
    #
    # Saved caches greatly improve cold-start speeds, and is relatively cheap in
    # terms of I/O for the key cache. Row cache saving is much more expensive and
    # has limited use.
    #
    # Default is 0 to disable saving the row cache.
    row_cache_save_period: 0
    
    # Number of keys from the row cache to save.
    # Specify 0 (which is the default), meaning all keys are going to be saved
    # row_cache_keys_to_save: 100
    
    # Maximum size of the counter cache in memory.
    #
    # Counter cache helps to reduce counter locks' contention for hot counter cells.
    # In case of RF = 1 a counter cache hit will cause Cassandra to skip the read before
    # write entirely. With RF > 1 a counter cache hit will still help to reduce the duration
    # of the lock hold, helping with hot counter cell updates, but will not allow skipping
    # the read entirely. Only the local (clock, count) tuple of a counter cell is kept
    # in memory, not the whole counter, so it's relatively cheap.
    #
    # NOTE: if you reduce the size, you may not get you hottest keys loaded on startup.
    #
    # Default value is empty to make it "auto" (min(2.5% of Heap (in MB), 50MB)). Set to 0 to disable counter cache.
    # NOTE: if you perform counter deletes and rely on low gcgs, you should disable the counter cache.
    counter_cache_size_in_mb:
    
    # Duration in seconds after which Cassandra should
    # save the counter cache (keys only). Caches are saved to saved_caches_directory as
    # specified in this configuration file.
    #
    # Default is 7200 or 2 hours.
    counter_cache_save_period: 7200
    
    # Number of keys from the counter cache to save
    # Disabled by default, meaning all keys are going to be saved
    # counter_cache_keys_to_save: 100
    
    # saved caches
    # If not set, the default directory is $CASSANDRA_HOME/data/saved_caches.
    saved_caches_directory: /var/lib/cassandra/saved_caches
    
    # commitlog_sync may be either "periodic" or "batch."
    # 
    # When in batch mode, Cassandra won't ack writes until the commit log
    # has been fsynced to disk.  It will wait
    # commitlog_sync_batch_window_in_ms milliseconds between fsyncs.
    # This window should be kept short because the writer threads will
    # be unable to do extra work while waiting.  (You may need to increase
    # concurrent_writes for the same reason.)
    #
    # commitlog_sync: batch
    # commitlog_sync_batch_window_in_ms: 2
    #
    # the other option is "periodic" where writes may be acked immediately
    # and the CommitLog is simply synced every commitlog_sync_period_in_ms
    # milliseconds.
    commitlog_sync: periodic
    commitlog_sync_period_in_ms: 10000
    
    # The size of the individual commitlog file segments.  A commitlog
    # segment may be archived, deleted, or recycled once all the data
    # in it (potentially from each columnfamily in the system) has been
    # flushed to sstables.
    #
    # The default size is 32, which is almost always fine, but if you are
    # archiving commitlog segments (see commitlog_archiving.properties),
    # then you probably want a finer granularity of archiving; 8 or 16 MB
    # is reasonable.
    # Max mutation size is also configurable via max_mutation_size_in_kb setting in
    # cassandra.yaml. The default is half the size commitlog_segment_size_in_mb * 1024.
    #
    # NOTE: If max_mutation_size_in_kb is set explicitly then commitlog_segment_size_in_mb must
    # be set to at least twice the size of max_mutation_size_in_kb / 1024
    #
    commitlog_segment_size_in_mb: 32
    
    # Compression to apply to the commit log. If omitted, the commit log
    # will be written uncompressed.  LZ4, Snappy, and Deflate compressors
    # are supported.
    #commitlog_compression:
    #   - class_name: LZ4Compressor
    #     parameters:
    #         -
    
    # any class that implements the SeedProvider interface and has a
    # constructor that takes a Map<String, String> of parameters will do.
    seed_provider:
        # Addresses of hosts that are deemed contact points.
        # Cassandra nodes use this list of hosts to find each other and learn
        # the topology of the ring.  You must change this if you are running
        # multiple nodes!
        #- class_name: io.k8s.cassandra.KubernetesSeedProvider
        - class_name: SEED_PROVIDER
          parameters:
              # seeds is actually a comma-delimited list of addresses.
              # Ex: "<ip1>,<ip2>,<ip3>"
              - seeds: "127.0.0.1"
    
    # For workloads with more data than can fit in memory, Cassandra's
    # bottleneck will be reads that need to fetch data from
    # disk. "concurrent_reads" should be set to (16 * number_of_drives) in
    # order to allow the operations to enqueue low enough in the stack
    # that the OS and drives can reorder them. Same applies to
    # "concurrent_counter_writes", since counter writes read the current
    # values before incrementing and writing them back.
    #
    # On the other hand, since writes are almost never IO bound, the ideal
    # number of "concurrent_writes" is dependent on the number of cores in
    # your system; (8 * number_of_cores) is a good rule of thumb.
    concurrent_reads: 32
    concurrent_writes: 32
    concurrent_counter_writes: 32
    
    # For materialized view writes, as there is a read involved, so this should
    # be limited by the less of concurrent reads or concurrent writes.
    concurrent_materialized_view_writes: 32
    
    # Maximum memory to use for pooling sstable buffers. Defaults to the smaller
    # of 1/4 of heap or 512MB. This pool is allocated off-heap, so is in addition
    # to the memory allocated for heap. Memory is only allocated as needed.
    # file_cache_size_in_mb: 512
    
    # Flag indicating whether to allocate on or off heap when the sstable buffer
    # pool is exhausted, that is when it has exceeded the maximum memory
    # file_cache_size_in_mb, beyond which it will not cache buffers but allocate on request.
    
    # buffer_pool_use_heap_if_exhausted: true
    
    # The strategy for optimizing disk read
    # Possible values are:
    # ssd (for solid state disks, the default)
    # spinning (for spinning disks)
    # disk_optimization_strategy: ssd
    
    # Total permitted memory to use for memtables. Cassandra will stop
    # accepting writes when the limit is exceeded until a flush completes,
    # and will trigger a flush based on memtable_cleanup_threshold
    # If omitted, Cassandra will set both to 1/4 the size of the heap.
    # memtable_heap_space_in_mb: 2048
    # memtable_offheap_space_in_mb: 2048
    
    # Ratio of occupied non-flushing memtable size to total permitted size
    # that will trigger a flush of the largest memtable. Larger mct will
    # mean larger flushes and hence less compaction, but also less concurrent
    # flush activity which can make it difficult to keep your disks fed
    # under heavy write load.
    #
    # memtable_cleanup_threshold defaults to 1 / (memtable_flush_writers + 1)
    # memtable_cleanup_threshold: 0.11
    
    # Specify the way Cassandra allocates and manages memtable memory.
    # Options are:
    #   heap_buffers:    on heap nio buffers
    #   offheap_buffers: off heap (direct) nio buffers
    #   offheap_objects: off heap objects
    memtable_allocation_type: offheap_objects
    
    # Total space to use for commit logs on disk.
    #
    # If space gets above this value, Cassandra will flush every dirty CF
    # in the oldest segment and remove it.  So a small total commitlog space
    # will tend to cause more flush activity on less-active columnfamilies.
    #
    # The default value is the smaller of 8192, and 1/4 of the total space
    # of the commitlog volume.
    #
    # commitlog_total_space_in_mb: 8192
    
    # This sets the amount of memtable flush writer threads.  These will
    # be blocked by disk io, and each one will hold a memtable in memory
    # while blocked.
    #
    # memtable_flush_writers defaults to one per data_file_directory.
    #
    # If your data directories are backed by SSD, you can increase this, but
    # avoid having memtable_flush_writers * data_file_directories > number of cores
    memtable_flush_writers: 2
    
    # A fixed memory pool size in MB for for SSTable index summaries. If left
    # empty, this will default to 5% of the heap size. If the memory usage of
    # all index summaries exceeds this limit, SSTables with low read rates will
    # shrink their index summaries in order to meet this limit.  However, this
    # is a best-effort process. In extreme conditions Cassandra may need to use
    # more than this amount of memory.
    index_summary_capacity_in_mb:
    
    # How frequently index summaries should be resampled.  This is done
    # periodically to redistribute memory from the fixed-size pool to sstables
    # proportional their recent read rates.  Setting to -1 will disable this
    # process, leaving existing index summaries at their current sampling level.
    index_summary_resize_interval_in_minutes: 60
    
    # Whether to, when doing sequential writing, fsync() at intervals in
    # order to force the operating system to flush the dirty
    # buffers. Enable this to avoid sudden dirty buffer flushing from
    # impacting read latencies. Almost always a good idea on SSDs; not
    # necessarily on platters.
    trickle_fsync: false
    trickle_fsync_interval_in_kb: 10240
    
    # TCP port, for commands and data
    # For security reasons, you should not expose this port to the internet.  Firewall it if needed.
    storage_port: 7000
    
    # SSL port, for encrypted communication.  Unused unless enabled in
    # encryption_options
    # For security reasons, you should not expose this port to the internet.  Firewall it if needed.
    ssl_storage_port: 7001
    
    # Address or interface to bind to and tell other Cassandra nodes to connect to.
    # You _must_ change this if you want multiple nodes to be able to communicate!
    #
    # Set listen_address OR listen_interface, not both. Interfaces must correspond
    # to a single address, IP aliasing is not supported.
    #
    # Leaving it blank leaves it up to InetAddress.getLocalHost(). This
    # will always do the Right Thing _if_ the node is properly configured
    # (hostname, name resolution, etc), and the Right Thing is to use the
    # address associated with the hostname (it might not be).
    #
    # Setting listen_address to 0.0.0.0 is always wrong.
    #
    # If you choose to specify the interface by name and the interface has an ipv4 and an ipv6 address
    # you can specify which should be chosen using listen_interface_prefer_ipv6. If false the first ipv4
    # address will be used. If true the first ipv6 address will be used. Defaults to false preferring
    # ipv4. If there is only one address it will be selected regardless of ipv4/ipv6.
    #listen_address: localhost
    # listen_interface: eth0
    # listen_interface_prefer_ipv6: false
    
    # Address to broadcast to other Cassandra nodes
    # Leaving this blank will set it to the same value as listen_address
    # broadcast_address: 1.2.3.4
    
    # When using multiple physical network interfaces, set this
    # to true to listen on broadcast_address in addition to
    # the listen_address, allowing nodes to communicate in both
    # interfaces.
    # Ignore this property if the network configuration automatically
    # routes  between the public and private networks such as EC2.
    # listen_on_broadcast_address: false
    
    # Internode authentication backend, implementing IInternodeAuthenticator;
    # used to allow/disallow connections from peer nodes.
    # internode_authenticator: org.apache.cassandra.auth.AllowAllInternodeAuthenticator
    
    # Whether to start the native transport server.
    # Please note that the address on which the native transport is bound is the
    # same as the rpc_address. The port however is different and specified below.
    start_native_transport: true
    # port for the CQL native transport to listen for clients on
    # For security reasons, you should not expose this port to the internet.  Firewall it if needed.
    native_transport_port: 9042
    # Enabling native transport encryption in client_encryption_options allows you to either use
    # encryption for the standard port or to use a dedicated, additional port along with the unencrypted
    # standard native_transport_port.
    # Enabling client encryption and keeping native_transport_port_ssl disabled will use encryption
    # for native_transport_port. Setting native_transport_port_ssl to a different value
    # from native_transport_port will use encryption for native_transport_port_ssl while
    # keeping native_transport_port unencrypted.
    # native_transport_port_ssl: 9142
    # The maximum threads for handling requests when the native transport is used.
    # This is similar to rpc_max_threads though the default differs slightly (and
    # there is no native_transport_min_threads, idle threads will always be stopped
    # after 30 seconds).
    # native_transport_max_threads: 128
    #
    # The maximum size of allowed frame. Frame (requests) larger than this will
    # be rejected as invalid. The default is 256MB.
    # native_transport_max_frame_size_in_mb: 256
    
    # The maximum number of concurrent client connections.
    # The default is -1, which means unlimited.
    # native_transport_max_concurrent_connections: -1
    
    # The maximum number of concurrent client connections per source ip.
    # The default is -1, which means unlimited.
    # native_transport_max_concurrent_connections_per_ip: -1
    
    # Whether to start the thrift rpc server.
    start_rpc: false
    
    # The address or interface to bind the Thrift RPC service and native transport
    # server to.
    #
    # Set rpc_address OR rpc_interface, not both. Interfaces must correspond
    # to a single address, IP aliasing is not supported.
    #
    # Leaving rpc_address blank has the same effect as on listen_address
    # (i.e. it will be based on the configured hostname of the node).
    #
    # Note that unlike listen_address, you can specify 0.0.0.0, but you must also
    # set broadcast_rpc_address to a value other than 0.0.0.0.
    #
    # For security reasons, you should not expose this port to the internet.  Firewall it if needed.
    #
    # If you choose to specify the interface by name and the interface has an ipv4 and an ipv6 address
    # you can specify which should be chosen using rpc_interface_prefer_ipv6. If false the first ipv4
    # address will be used. If true the first ipv6 address will be used. Defaults to false preferring
    # ipv4. If there is only one address it will be selected regardless of ipv4/ipv6.
    rpc_address: 0.0.0.0
    # rpc_interface: eth1
    # rpc_interface_prefer_ipv6: false
    
    # port for Thrift to listen for clients on
    rpc_port: 9160
    
    # RPC address to broadcast to drivers and other Cassandra nodes. This cannot
    # be set to 0.0.0.0. If left blank, this will be set to the value of
    # rpc_address. If rpc_address is set to 0.0.0.0, broadcast_rpc_address must
    # be set.
    # broadcast_rpc_address: 1.2.3.4
    
    # enable or disable keepalive on rpc/native connections
    rpc_keepalive: true
    
    # Cassandra provides two out-of-the-box options for the RPC Server:
    #
    # sync  -> One thread per thrift connection. For a very large number of clients, memory
    #          will be your limiting factor. On a 64 bit JVM, 180KB is the minimum stack size
    #          per thread, and that will correspond to your use of virtual memory (but physical memory
    #          may be limited depending on use of stack space).
    #
    # hsha  -> Stands for "half synchronous, half asynchronous." All thrift clients are handled
    #          asynchronously using a small number of threads that does not vary with the amount
    #          of thrift clients (and thus scales well to many clients). The rpc requests are still
    #          synchronous (one thread per active request). If hsha is selected then it is essential
    #          that rpc_max_threads is changed from the default value of unlimited.
    #
    # The default is sync because on Windows hsha is about 30% slower.  On Linux,
    # sync/hsha performance is about the same, with hsha of course using less memory.
    #
    # Alternatively,  can provide your own RPC server by providing the fully-qualified class name
    # of an o.a.c.t.TServerFactory that can create an instance of it.
    rpc_server_type: sync
    
    # Uncomment rpc_min|max_thread to set request pool size limits.
    #
    # Regardless of your choice of RPC server (see above), the number of maximum requests in the
    # RPC thread pool dictates how many concurrent requests are possible (but if you are using the sync
    # RPC server, it also dictates the number of clients that can be connected at all).
    #
    # The default is unlimited and thus provides no protection against clients overwhelming the server. You are
    # encouraged to set a maximum that makes sense for you in production, but do keep in mind that
    # rpc_max_threads represents the maximum number of client requests this server may execute concurrently.
    #
    # rpc_min_threads: 16
    # rpc_max_threads: 2048
    
    # uncomment to set socket buffer sizes on rpc connections
    # rpc_send_buff_size_in_bytes:
    # rpc_recv_buff_size_in_bytes:
    
    # Uncomment to set socket buffer size for internode communication
    # Note that when setting this, the buffer size is limited by net.core.wmem_max
    # and when not setting it it is defined by net.ipv4.tcp_wmem
    # See:
    # /proc/sys/net/core/wmem_max
    # /proc/sys/net/core/rmem_max
    # /proc/sys/net/ipv4/tcp_wmem
    # /proc/sys/net/ipv4/tcp_wmem
    # and: man tcp
    # internode_send_buff_size_in_bytes:
    # internode_recv_buff_size_in_bytes:
    
    # Frame size for thrift (maximum message length).
    thrift_framed_transport_size_in_mb: 15
    
    # Set to true to have Cassandra create a hard link to each sstable
    # flushed or streamed locally in a backups/ subdirectory of the
    # keyspace data.  Removing these links is the operator's
    # responsibility.
    incremental_backups: false
    
    # Whether or not to take a snapshot before each compaction.  Be
    # careful using this option, since Cassandra won't clean up the
    # snapshots for you.  Mostly useful if you're paranoid when there
    # is a data format change.
    snapshot_before_compaction: false
    
    # Whether or not a snapshot is taken of the data before keyspace truncation
    # or dropping of column families. The STRONGLY advised default of true
    # should be used to provide data safety. If you set this flag to false, you will
    # lose data on truncation or drop.
    auto_snapshot: false
    
    # When executing a scan, within or across a partition, we need to keep the
    # tombstones seen in memory so we can return them to the coordinator, which
    # will use them to make sure other replicas also know about the deleted rows.
    # With workloads that generate a lot of tombstones, this can cause performance
    # problems and even exaust the server heap.
    # (http://www.datastax.com/dev/blog/cassandra-anti-patterns-queues-and-queue-like-datasets)
    # Adjust the thresholds here if you understand the dangers and want to
    # scan more tombstones anyway.  These thresholds may also be adjusted at runtime
    # using the StorageService mbean.
    tombstone_warn_threshold: 1000
    tombstone_failure_threshold: 100000
    
    # Granularity of the collation index of rows within a partition.
    # Increase if your rows are large, or if you have a very large
    # number of rows per partition.  The competing goals are these:
    #   1) a smaller granularity means more index entries are generated
    #      and looking up rows within the partition by collation column
    #      is faster
    #   2) but, Cassandra will keep the collation index in memory for hot
    #      rows (as part of the key cache), so a larger granularity means
    #      you can cache more hot rows
    column_index_size_in_kb: 64
    
    
    # Log WARN on any batch size exceeding this value. 5kb per batch by default.
    # Caution should be taken on increasing the size of this threshold as it can lead to node instability.
    batch_size_warn_threshold_in_kb: 5
    
    # Fail any batch exceeding this value. 50kb (10x warn threshold) by default.
    batch_size_fail_threshold_in_kb: 50
    
    # Number of simultaneous compactions to allow, NOT including
    # validation "compactions" for anti-entropy repair.  Simultaneous
    # compactions can help preserve read performance in a mixed read/write
    # workload, by mitigating the tendency of small sstables to accumulate
    # during a single long running compactions. The default is usually
    # fine and if you experience problems with compaction running too
    # slowly or too fast, you should look at
    # compaction_throughput_mb_per_sec first.
    #
    # concurrent_compactors defaults to the smaller of (number of disks,
    # number of cores), with a minimum of 2 and a maximum of 8.
    #
    # If your data directories are backed by SSD, you should increase this
    # to the number of cores.
    #concurrent_compactors: 1
    
    # Throttles compaction to the given total throughput across the entire
    # system. The faster you insert data, the faster you need to compact in
    # order to keep the sstable count down, but in general, setting this to
    # 16 to 32 times the rate you are inserting data is more than sufficient.
    # Setting this to 0 disables throttling. Note that this account for all types
    # of compaction, including validation compaction.
    compaction_throughput_mb_per_sec: 16
    
    # Log a warning when compacting partitions larger than this value
    compaction_large_partition_warning_threshold_mb: 100
    
    # When compacting, the replacement sstable(s) can be opened before they
    # are completely written, and used in place of the prior sstables for
    # any range that has been written. This helps to smoothly transfer reads
    # between the sstables, reducing page cache churn and keeping hot rows hot
    sstable_preemptive_open_interval_in_mb: 50
    
    # Throttles all outbound streaming file transfers on this node to the
    # given total throughput in Mbps. This is necessary because Cassandra does
    # mostly sequential IO when streaming data during bootstrap or repair, which
    # can lead to saturating the network connection and degrading rpc performance.
    # When unset, the default is 200 Mbps or 25 MB/s.
    # stream_throughput_outbound_megabits_per_sec: 200
    
    # Throttles all streaming file transfer between the datacenters,
    # this setting allows users to throttle inter dc stream throughput in addition
    # to throttling all network stream traffic as configured with
    # stream_throughput_outbound_megabits_per_sec
    # When unset, the default is 200 Mbps or 25 MB/s
    # inter_dc_stream_throughput_outbound_megabits_per_sec: 200
    
    # How long the coordinator should wait for read operations to complete
    read_request_timeout_in_ms: 5000
    # How long the coordinator should wait for seq or index scans to complete
    range_request_timeout_in_ms: 10000
    # How long the coordinator should wait for writes to complete
    write_request_timeout_in_ms: 5000
    # How long the coordinator should wait for counter writes to complete
    counter_write_request_timeout_in_ms: 5000
    # How long a coordinator should continue to retry a CAS operation
    # that contends with other proposals for the same row
    cas_contention_timeout_in_ms: 1000
    # How long the coordinator should wait for truncates to complete
    # (This can be much longer, because unless auto_snapshot is disabled
    # we need to flush first so we can snapshot before removing the data.)
    truncate_request_timeout_in_ms: 60000
    # The default timeout for other, miscellaneous operations
    request_timeout_in_ms: 10000
    
    # Enable operation timeout information exchange between nodes to accurately
    # measure request timeouts.  If disabled, replicas will assume that requests
    # were forwarded to them instantly by the coordinator, which means that
    # under overload conditions we will waste that much extra time processing
    # already-timed-out requests.
    #
    # Warning: before enabling this property make sure to ntp is installed
    # and the times are synchronized between the nodes.
    cross_node_timeout: false
    
    # Set socket timeout for streaming operation.
    # The stream session is failed if no data is received by any of the
    # participants within that period.
    # Default value is 3600000, which means streams timeout after an hour.
    # streaming_socket_timeout_in_ms: 3600000
    
    # phi value that must be reached for a host to be marked down.
    # most users should never need to adjust this.
    # phi_convict_threshold: 8
    
    # endpoint_snitch -- Set this to a class that implements
    # IEndpointSnitch.  The snitch has two functions:
    # - it teaches Cassandra enough about your network topology to route
    #   requests efficiently
    # - it allows Cassandra to spread replicas around your cluster to avoid
    #   correlated failures. It does this by grouping machines into
    #   "datacenters" and "racks."  Cassandra will do its best not to have
    #   more than one replica on the same "rack" (which may not actually
    #   be a physical location)
    #
    # IF YOU CHANGE THE SNITCH AFTER DATA IS INSERTED INTO THE CLUSTER,
    # YOU MUST RUN A FULL REPAIR, SINCE THE SNITCH AFFECTS WHERE REPLICAS
    # ARE PLACED.
    #
    # IF THE RACK A REPLICA IS PLACED IN CHANGES AFTER THE REPLICA HAS BEEN
    # ADDED TO A RING, THE NODE MUST BE DECOMMISSIONED AND REBOOTSTRAPPED.
    #
    # Out of the box, Cassandra provides
    #  - SimpleSnitch:
    #    Treats Strategy order as proximity. This can improve cache
    #    locality when disabling read repair.  Only appropriate for
    #    single-datacenter deployments.
    #  - GossipingPropertyFileSnitch
    #    This should be your go-to snitch for production use.  The rack
    #    and datacenter for the local node are defined in
    #    cassandra-rackdc.properties and propagated to other nodes via
    #    gossip.  If cassandra-topology.properties exists, it is used as a
    #    fallback, allowing migration from the PropertyFileSnitch.
    #  - PropertyFileSnitch:
    #    Proximity is determined by rack and data center, which are
    #    explicitly configured in cassandra-topology.properties.
    #  - Ec2Snitch:
    #    Appropriate for EC2 deployments in a single Region. Loads Region
    #    and Availability Zone information from the EC2 API. The Region is
    #    treated as the datacenter, and the Availability Zone as the rack.
    #    Only private IPs are used, so this will not work across multiple
    #    Regions.
    #  - Ec2MultiRegionSnitch:
    #    Uses public IPs as broadcast_address to allow cross-region
    #    connectivity.  (Thus, you should set seed addresses to the public
    #    IP as well.) You will need to open the storage_port or
    #    ssl_storage_port on the public IP firewall.  (For intra-Region
    #    traffic, Cassandra will switch to the private IP after
    #    establishing a connection.)
    #  - RackInferringSnitch:
    #    Proximity is determined by rack and data center, which are
    #    assumed to correspond to the 3rd and 2nd octet of each node's IP
    #    address, respectively.  Unless this happens to match your
    #    deployment conventions, this is best used as an example of
    #    writing a custom Snitch class and is provided in that spirit.
    #
    # You can use a custom Snitch by setting this to the full class name
    # of the snitch, which will be assumed to be on your classpath.
    endpoint_snitch: SimpleSnitch
    
    dynamic_snitch: false
    # controls how often to perform the more expensive part of host score
    # calculation
    dynamic_snitch_update_interval_in_ms: 100
    # controls how often to reset all host scores, allowing a bad host to
    # possibly recover
    dynamic_snitch_reset_interval_in_ms: 600000
    # if set greater than zero and read_repair_chance is < 1.0, this will allow
    # 'pinning' of replicas to hosts in order to increase cache capacity.
    # The badness threshold will control how much worse the pinned host has to be
    # before the dynamic snitch will prefer other replicas over it.  This is
    # expressed as a double which represents a percentage.  Thus, a value of
    # 0.2 means Cassandra would continue to prefer the static snitch values
    # until the pinned host was 20% worse than the fastest.
    dynamic_snitch_badness_threshold: 0.1
    
    # request_scheduler -- Set this to a class that implements
    # RequestScheduler, which will schedule incoming client requests
    # according to the specific policy. This is useful for multi-tenancy
    # with a single Cassandra cluster.
    # NOTE: This is specifically for requests from the client and does
    # not affect inter node communication.
    # org.apache.cassandra.scheduler.NoScheduler - No scheduling takes place
    # org.apache.cassandra.scheduler.RoundRobinScheduler - Round robin of
    # client requests to a node with a separate queue for each
    # request_scheduler_id. The scheduler is further customized by
    # request_scheduler_options as described below.
    request_scheduler: org.apache.cassandra.scheduler.NoScheduler
    
    # Scheduler Options vary based on the type of scheduler
    # NoScheduler - Has no options
    # RoundRobin
    #  - throttle_limit -- The throttle_limit is the number of in-flight
    #                      requests per client.  Requests beyond
    #                      that limit are queued up until
    #                      running requests can complete.
    #                      The value of 80 here is twice the number of
    #                      concurrent_reads + concurrent_writes.
    #  - default_weight -- default_weight is optional and allows for
    #                      overriding the default which is 1.
    #  - weights -- Weights are optional and will default to 1 or the
    #               overridden default_weight. The weight translates into how
    #               many requests are handled during each turn of the
    #               RoundRobin, based on the scheduler id.
    #
    # request_scheduler_options:
    #    throttle_limit: 80
    #    default_weight: 5
    #    weights:
    #      Keyspace1: 1
    #      Keyspace2: 5
    
    # request_scheduler_id -- An identifier based on which to perform
    # the request scheduling. Currently the only valid option is keyspace.
    # request_scheduler_id: keyspace
    
    # Enable or disable inter-node encryption
    # Default settings are TLS v1, RSA 1024-bit keys (it is imperative that
    # users generate their own keys) TLS_RSA_WITH_AES_128_CBC_SHA as the cipher
    # suite for authentication, key exchange and encryption of the actual data transfers.
    # Use the DHE/ECDHE ciphers if running in FIPS 140 compliant mode.
    # NOTE: No custom encryption options are enabled at the moment
    # The available internode options are : all, none, dc, rack
    #
    # If set to dc cassandra will encrypt the traffic between the DCs
    # If set to rack cassandra will encrypt the traffic between the racks
    #
    # The passwords used in these options must match the passwords used when generating
    # the keystore and truststore.  For instructions on generating these files, see:
    # http://download.oracle.com/javase/6/docs/technotes/guides/security/jsse/JSSERefGuide.html#CreateKeystore
    #
    server_encryption_options:
        internode_encryption: none
        keystore: conf/.keystore
        keystore_password: cassandra
        truststore: conf/.truststore
        truststore_password: cassandra
        # More advanced defaults below:
        # protocol: TLS
        # algorithm: SunX509
        # store_type: JKS
        # cipher_suites: [TLS_RSA_WITH_AES_128_CBC_SHA,TLS_RSA_WITH_AES_256_CBC_SHA,TLS_DHE_RSA_WITH_AES_128_CBC_SHA,TLS_DHE_RSA_WITH_AES_256_CBC_SHA,TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA,TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA]
        # require_client_auth: false
    
    # enable or disable client/server encryption.
    client_encryption_options:
        enabled: false
        # If enabled and optional is set to true encrypted and unencrypted connections are handled.
        optional: false
        keystore: conf/.keystore
        keystore_password: cassandra
        # require_client_auth: false
        # Set trustore and truststore_password if require_client_auth is true
        # truststore: conf/.truststore
        # truststore_password: cassandra
        # More advanced defaults below:
        # protocol: TLS
        # algorithm: SunX509
        # store_type: JKS
        # cipher_suites: [TLS_RSA_WITH_AES_128_CBC_SHA,TLS_RSA_WITH_AES_256_CBC_SHA,TLS_DHE_RSA_WITH_AES_128_CBC_SHA,TLS_DHE_RSA_WITH_AES_256_CBC_SHA,TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA,TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA]
    
    # internode_compression controls whether traffic between nodes is
    # compressed.
    # can be:  all  - all traffic is compressed
    #          dc   - traffic between different datacenters is compressed
    #          none - nothing is compressed.
    internode_compression: all
    
    # Enable or disable tcp_nodelay for inter-dc communication.
    # Disabling it will result in larger (but fewer) network packets being sent,
    # reducing overhead from the TCP protocol itself, at the cost of increasing
    # latency if you block for cross-datacenter responses.
    inter_dc_tcp_nodelay: false
    
    # TTL for different trace types used during logging of the repair process.
    tracetype_query_ttl: 86400
    tracetype_repair_ttl: 604800
    
    # GC Pauses greater than gc_warn_threshold_in_ms will be logged at WARN level
    # Adjust the threshold based on your application throughput requirement
    # By default, Cassandra logs GC Pauses greater than 200 ms at INFO level
    gc_warn_threshold_in_ms: 1000
    
    # UDFs (user defined functions) are disabled by default.
    # As of Cassandra 3.0 there is a sandbox in place that should prevent execution of evil code.
    enable_user_defined_functions: false
    
    # Enables scripted UDFs (JavaScript UDFs).
    # Java UDFs are always enabled, if enable_user_defined_functions is true.
    # Enable this option to be able to use UDFs with "language javascript" or any custom JSR-223 provider.
    # This option has no effect, if enable_user_defined_functions is false.
    enable_scripted_user_defined_functions: false
    
    # The default Windows kernel timer and scheduling resolution is 15.6ms for power conservation.
    # Lowering this value on Windows can provide much tighter latency and better throughput, however
    # some virtualized environments may see a negative performance impact from changing this setting
    # below their system default. The sysinternals 'clockres' tool can confirm your system's default
    # setting.
    windows_timer_interval: 1
    
    
    # Enables encrypting data at-rest (on disk). Different key providers can be plugged in, but the default reads from
    # a JCE-style keystore. A single keystore can hold multiple keys, but the one referenced by
    # the "key_alias" is the only key that will be used for encrypt opertaions; previously used keys
    # can still (and should!) be in the keystore and will be used on decrypt operations
    # (to handle the case of key rotation).
    #
    # It is strongly recommended to download and install Java Cryptography Extension (JCE)
    # Unlimited Strength Jurisdiction Policy Files for your version of the JDK.
    # (current link: http://www.oracle.com/technetwork/java/javase/downloads/jce8-download-2133166.html)
    #
    # Currently, only the following file types are supported for transparent data encryption, although
    # more are coming in future cassandra releases: commitlog, hints
    transparent_data_encryption_options:
        enabled: false
        chunk_length_kb: 64
        cipher: AES/CBC/PKCS5Padding
        key_alias: testing:1
        # CBC IV length for AES needs to be 16 bytes (which is also the default size)
        # iv_length: 16
        key_provider: 
          - class_name: org.apache.cassandra.security.JKSKeyProvider
            parameters: 
              - keystore: conf/.keystore
                keystore_password: cassandra
                store_type: JCEKS
                key_password: cassandra
    
  jvm.options: |
    ###########################################################################
    #                   jvm.options (from CONFIGMAP)                          #
    #                                                                         #
    # - all flags defined here will be used by cassandra to startup the JVM   #
    # - one flag should be specified per line                                 #
    # - lines that do not start with '-' will be ignored                      #
    # - only static flags are accepted (no variables or parameters)           #
    # - dynamic flags will be appended to these on cassandra-env              #
    ###########################################################################
    
    ######################
    # STARTUP PARAMETERS #
    ######################
    
    # Uncomment any of the following properties to enable specific startup parameters
    
    # In a multi-instance deployment, multiple Cassandra instances will independently assume that all
    # CPU processors are available to it. This setting allows you to specify a smaller set of processors
    # and perhaps have affinity.
    #-Dcassandra.available_processors=number_of_processors
    
    # The directory location of the cassandra.yaml file.
    #-Dcassandra.config=directory
    
    # Sets the initial partitioner token for a node the first time the node is started.
    #-Dcassandra.initial_token=token
    
    # Set to false to start Cassandra on a node but not have the node join the cluster.
    #-Dcassandra.join_ring=true|false
    
    # Set to false to clear all gossip state for the node on restart. Use when you have changed node
    # information in cassandra.yaml (such as listen_address).
    #-Dcassandra.load_ring_state=true|false
    
    # Enable pluggable metrics reporter. See Pluggable metrics reporting in Cassandra 2.0.2.
    #-Dcassandra.metricsReporterConfigFile=file
    
    # Set the port on which the CQL native transport listens for clients. (Default: 9042)
    #-Dcassandra.native_transport_port=port
    
    # Overrides the partitioner. (Default: org.apache.cassandra.dht.Murmur3Partitioner)
    #-Dcassandra.partitioner=partitioner
    
    # To replace a node that has died, restart a new node in its place specifying the address of the
    # dead node. The new node must not have any data in its data directory, that is, it must be in the
    # same state as before bootstrapping.
    #-Dcassandra.replace_address=listen_address or broadcast_address of dead node
    
    # Allow restoring specific tables from an archived commit log.
    #-Dcassandra.replayList=table
    
    # Allows overriding of the default RING_DELAY (1000ms), which is the amount of time a node waits
    # before joining the ring.
    #-Dcassandra.ring_delay_ms=ms
    
    # Set the port for the Thrift RPC service, which is used for client connections. (Default: 9160)
    #-Dcassandra.rpc_port=port
    
    # Set the SSL port for encrypted communication. (Default: 7001)
    #-Dcassandra.ssl_storage_port=port
    
    # Enable or disable the native transport server. See start_native_transport in cassandra.yaml.
    # cassandra.start_native_transport=true|false
    
    # Enable or disable the Thrift RPC server. (Default: true)
    #-Dcassandra.start_rpc=true/false
    
    # Set the port for inter-node communication. (Default: 7000)
    #-Dcassandra.storage_port=port
    
    # Set the default location for the trigger JARs. (Default: conf/triggers)
    #-Dcassandra.triggers_dir=directory
    
    # For testing new compaction and compression strategies. It allows you to experiment with different
    # strategies and benchmark write performance differences without affecting the production workload.
    #-Dcassandra.write_survey=true
    
    # To disable configuration via JMX of auth caches (such as those for credentials, permissions and
    # roles). This will mean those config options can only be set (persistently) in cassandra.yaml
    # and will require a restart for new values to take effect.
    #-Dcassandra.disable_auth_caches_remote_configuration=true
    
    ########################
    # GENERAL JVM SETTINGS #
    ########################
    
    # enable assertions.  disabling this in production will give a modest
    # performance benefit (around 5%).
    # -ea
    
    # enable thread priorities, primarily so we can give periodic tasks
    # a lower priority to avoid interfering with client workload
    -XX:+UseThreadPriorities
    
    # allows lowering thread priority without being root on linux - probably
    # not necessary on Windows but doesn't harm anything.
    # see http://tech.stolsvik.com/2010/01/linux-java-thread-priorities-workar
    -XX:ThreadPriorityPolicy=42
    
    # Enable heap-dump if there's an OOM
    -XX:+HeapDumpOnOutOfMemoryError
    
    # Per-thread stack size.
    -Xss256k
    
    # Larger interned string table, for gossip's benefit (CASSANDRA-6410)
    -XX:StringTableSize=1000003
    
    # Make sure all memory is faulted and zeroed on startup.
    # This helps prevent soft faults in containers and makes
    # transparent hugepage allocation more effective.
    -XX:+AlwaysPreTouch
    
    # Disable biased locking as it does not benefit Cassandra.
    -XX:-UseBiasedLocking
    
    # Enable thread-local allocation blocks and allow the JVM to automatically
    # resize them at runtime.
    -XX:+UseTLAB
    -XX:+ResizeTLAB
    
    # http://www.evanjones.ca/jvm-mmap-pause.html
    # Prevent Jolokia from working see https://jira.apache.org/jira/browse/CASSANDRA-9483
    #-XX:+PerfDisableSharedMem
    
    # Prefer binding to IPv4 network intefaces (when net.ipv6.bindv6only=1). See
    # http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=6342561 (short version:
    # comment out this entry to enable IPv6 support).
    -Djava.net.preferIPv4Stack=true
    
    ### Debug options
    
    # uncomment to enable flight recorder
    #-XX:+UnlockCommercialFeatures
    #-XX:+FlightRecorder
    
    # uncomment to have Cassandra JVM listen for remote debuggers/profilers on port 1414
    #-agentlib:jdwp=transport=dt_socket,server=y,suspend=n,address=1414
    
    # uncomment to have Cassandra JVM log internal method compilation (developers only)
    #-XX:+UnlockDiagnosticVMOptions
    #-XX:+LogCompilation
    
    #################
    # HEAP SETTINGS #
    #################
    
    # Heap size is automatically calculated by cassandra-env based on this
    # formula: max(min(1/2 ram, 1024MB), min(1/4 ram, 8GB))
    # That is:
    # - calculate 1/2 ram and cap to 1024MB
    # - calculate 1/4 ram and cap to 8192MB
    # - pick the max
    #
    # For production use you may wish to adjust this for your environment.
    # If that's the case, uncomment the -Xmx and Xms options below to override the
    # automatic calculation of JVM heap memory.
    #
    # It is recommended to set min (-Xms) and max (-Xmx) heap sizes to
    # the same value to avoid stop-the-world GC pauses during resize, and
    # so that we can lock the heap in memory on startup to prevent any
    # of it from being swapped out.
    #-Xms4G
    #-Xmx4G
    
    # Young generation size is automatically calculated by cassandra-env
    # based on this formula: min(100 * num_cores, 1/4 * heap size)
    #
    # The main trade-off for the young generation is that the larger it
    # is, the longer GC pause times will be. The shorter it is, the more
    # expensive GC will be (usually).
    #
    # It is not recommended to set the young generation size if using the
    # G1 GC, since that will override the target pause-time goal.
    # More info: http://www.oracle.com/technetwork/articles/java/g1gc-1984535.html
    #
    # The example below assumes a modern 8-core+ machine for decent
    # times. If in doubt, and if you do not particularly want to tweak, go
    # 100 MB per physical CPU core.
    #-Xmn800M
    
    #################
    #  GC SETTINGS  #
    #################
    
    ### CMS Settings
    
    #-XX:+UseParNewGC
    #-XX:+UseConcMarkSweepGC
    #-XX:+CMSParallelRemarkEnabled
    #-XX:SurvivorRatio=8
    #-XX:MaxTenuringThreshold=1
    #-XX:CMSInitiatingOccupancyFraction=75
    #-XX:+UseCMSInitiatingOccupancyOnly
    #-XX:CMSWaitDuration=10000
    #-XX:+CMSParallelInitialMarkEnabled
    #-XX:+CMSEdenChunksRecordAlways
    # some JVMs will fill up their heap when accessed via JMX, see CASSANDRA-6541
    #-XX:+CMSClassUnloadingEnabled
    
    ### G1 Settings (experimental, comment previous section and uncomment section below to enable)
    
    ## Use the Hotspot garbage-first collector.
    -XX:+UseG1GC
    #
    ## Have the JVM do less remembered set work during STW, instead
    ## preferring concurrent GC. Reduces p99.9 latency.
    -XX:G1RSetUpdatingPauseTimePercent=5
    #
    ## Main G1GC tunable: lowering the pause target will lower throughput and vise versa.
    ## 200ms is the JVM default and lowest viable setting
    ## 1000ms increases throughput. Keep it smaller than the timeouts in cassandra.yaml.
    #-XX:MaxGCPauseMillis=500
    
    ## Optional G1 Settings
    
    # Save CPU time on large (>= 16GB) heaps by delaying region scanning
    # until the heap is 70% full. The default in Hotspot 8u40 is 40%.
    #-XX:InitiatingHeapOccupancyPercent=70
    
    # For systems with > 8 cores, the default ParallelGCThreads is 5/8 the number of logical cores.
    # Otherwise equal to the number of cores when 8 or less.
    # Machines with > 10 cores should try setting these to <= full cores.
    #-XX:ParallelGCThreads=16
    # By default, ConcGCThreads is 1/4 of ParallelGCThreads.
    # Setting both to the same value can reduce STW durations.
    #-XX:ConcGCThreads=16
    
    ### GC logging options -- uncomment to enable
    
    -XX:+PrintGCDetails
    -XX:+PrintGCDateStamps
    -XX:+PrintHeapAtGC
    -XX:+PrintTenuringDistribution
    -XX:+PrintGCApplicationStoppedTime
    -XX:+PrintPromotionFailure
    #-XX:PrintFLSStatistics=1
    #-Xloggc:/var/log/cassandra/gc.log
    #-XX:+UseGCLogFileRotation
    #-XX:NumberOfGCLogFiles=10
    #-XX:GCLogFileSize=10M
    
    -javaagent:/usr/local/share/prometheus-agent.jar=1234:/etc/cassandra/prometheus.yaml
    
    # Debug
    -XX:+PrintCommandLineFlags
