Hi, I have a single node swift cluster. I measured the time taken to complete a PUT request that originated from three different client machines. Each client was writing a single 256K byte object.
Note that the time measured was only the time taken on the Swift cluster itself. I started the timer after the request was received by the swift proxy-server process and stopped it when that method returned an HTTP status to the client. This is not the time on the client side and therefore *ideally* should not be affected by the latency between the client and the Swift cluster. However, it appears that the above is not true. The time required to complete the request is related to the latency between the client and swift cluster. Here are the results: * Client 1: Ping time 28ms PUT request time: ~180 ms * Client 2: Ping time 4 ms PUT request time: ~35 ms * Client 3: Ping time 0.04 ms PUT request time: ~10 ms Details about the experiment: * This is a single node Swift installation (not devstack) and uses SSDs to store metadata as well as data. This is just a test setup. In production, we won't have SSDs for storing data. * The above numbers are average of 50 PUT requests. * The Swift cluster was not being used for anything else during the experiment. * The client used was the jclouds library written in java. I had disable a config option that used the Expect 100-Continue header; i.e. the requests were not using the Expect 100-Continue header. * I tried increasing the size of the following options in the proxy-server.conf and restarting Swift. disk_chunk_size = 262144 network_chunk_size = 262144 ... [app:proxy-server] object_chunk_size = 262144 client_chunk_size = 262144 However, this didn't show any improvement in the time required for PUT requests. Am I missing anything? Does Swift require an extra round trip from the client for completing PUT requests? Any ways of avoiding that? Thanks in advance. -Shri _______________________________________________ Mailing list: http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack Post to : openstack@lists.openstack.org Unsubscribe : http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack
