12908256
Improving Connection Management of the OpenLDAP Directory Server
This paper describes our effort to improve the performance of the connection management subsystem of the OpenLDAP directory server. Two proposed architectures, the multi-listener and the lightweight listener architectures, will be described and compared to each other. This paper will also describe our effort to improve the synchronization of multiple threads by introducing a semaphore based resource control scheme. The new connection management schemes proposed in this paper made the OpenLDAP directory server perform better in the presence of long latency operations and reduces the overhead caused by unnecessary context switching and inefficient event polling.
24658698
DNS: disk-to-network splicing for network driven data transferring
In Internet servers that run on general-purpose operating systems, network subsystems and disk subsystems cooperate with each other for user requests. Many studies have focused on optimizing the data movement across the subsystems to reduce data copying overhead among intermediate buffers such as process buffers, network send buffers and disk buffers. When data are moved across the subsystems, events such as read requests and write requests for data movement are also delivered across the subsystems by the servers and operating systems. However, there have been fewer studies on the optimization of event delivery which controls data copying timing across the subsystems. In conventional operating systems, to transfer data in the disk subsystem into the network subsystem, several different contexts are involved. A series of events are passed through the contexts. Whenever an event in one context is passed into the other context, context switching and scheduling are incurred. We have developed inter-subsystem event delivery mechanism, disk-to-network splicing (DNS), which optimizes event delivery among the subsystems involved to suppress scheduling and context switching during I/O request processing. We developed a DNS mechanism and performed experiments on Linux 2.4. The experimental results show that the system performance is improved by 4.9% 10.1%.
36007218
A Novel Geometric Algorithm for Fast Wire-Optimized Floorplanning