Give the best possible comprehensive response to this question: What is NAME_1 in a nutshell?
(Suggested answer: Cluster management system)
(Summary of full document: "The workload mix varies across cells, which run different mixes of applications depending on their major tenants (e.g., some cells are quite batch-intensive), and also varies over time: batch jobs come and go, and many end-user-facing service jobs see a diurnal usage pattern. 2.2 Clusters and cells The machines in a cell belong to a single cluster, defined by the high-performance datacenter-scale network fabric that connects them.")
(full document:"Many application frameworks have been built on top of
NAME_1 over the last few years, including our internal MapReduce system [23], FlumeJava [18], Millwheel [3], and Pregel
[59]. Most of these have a controller that submits a master
job and one or more worker jobs; the first two play a similar
role to YARN’s application manager [76]. Our distributed
storage systems such as GFS [34] and its successor CFS,
Bigtable [19], and Megastore [8] all run on NAME_1.
For this paper, we classify higher-priority NAME_1 jobs as
“production” (prod) ones, and the rest as “non-production”
(non-prod). Most long-running server jobs are prod; most
batch jobs are non-prod. In a representative cell, prod jobs
are allocated about 70% of the total CPU resources and represent about 60% of the total CPU usage; they are allocated
about 55% of the total memory and represent about 85% of
the total memory usage. The discrepancies between allocation and usage will prove important in §5.5.
2.2 Clusters and cells
The machines in a cell belong to a single cluster, defined by
the high-performance datacenter-scale network fabric that
connects them. A cluster lives inside a single datacenter
building, and a collection of buildings makes up a site.1
A cluster usually hosts one large cell and may have a few
smaller-scale test or special-purpose cells. We assiduously
avoid any single point of failure.
Our median cell size is about 10 k machines after excluding test cells; some are much larger. The machines in a cell
are heterogeneous in many dimensions: sizes (CPU, RAM,
disk, network), processor type, performance, and capabilities such as an external IP address or flash storage. NAME_1 isolates users from most of these differences by determining
where in a cell to run tasks, allocating their resources, installing their programs and other dependencies, monitoring
their health, and restarting them if they fail.
2.3 Jobs and tasks
A NAME_1 job’s properties inc