Hi Satoshi, This question would be better for the 'DataStax Java Driver for Apache Cassandra mailing list <https://groups.google.com/a/lists.datastax.com/forum/#%21forum/java-driver-user>', but I do have a few thoughts about what you are observing:
Between java-driver 2.1 and 3.0 the driver updated its Netty dependency from 3.9.x to 4.0.x. Cluster#close is likely taking two seconds longer because the driver uses AbstractEventExecutor.shutdownGracefully() <https://github.com/netty/netty/blob/netty-4.0.44.Final/common/src/main/java/io/netty/util/concurrent/AbstractEventExecutor.java#L50> which waits for a quiet period of 2 seconds to allow any inflight requests to complete. You can disable that by passing a custom NettyOptions <http://docs.datastax.com/en/drivers/java/3.1/com/datastax/driver/core/NettyOptions.html> to a Cluster.Builder using withNettyOptions, i.e.: /** * A custom {@link NettyOptions} that shuts down the {@link EventLoopGroup} after * no quiet time. This is useful for tests that consistently close clusters as * otherwise there is a 2 second delay (from JAVA-914 <https://datastax-oss.atlassian.net/browse/JAVA-914>). */ public static NettyOptions nonQuietClusterCloseOptions = new NettyOptions() { @Override public void onClusterClose(EventLoopGroup eventLoopGroup) { eventLoopGroup.shutdownGracefully(0, 15, SECONDS).syncUninterruptibly(); } }; However, I wouldn't recommend doing this unless you have a requirement for Cluster.close to be as qiuck as possible, as after all closing a Cluster frequently is not something you should expect to be doing often as a Cluster and it's Session are meant to be reused over the lifetime of an application. With regards to Cluster.connect being slower, i'm not sure I have an explanation for that and it is not something I have noticed. I would not expect Cluster.connect to even take a second with a single node cluster (for example, I recorded some numbers <https://datastax-oss.atlassian.net/browse/JAVA-692?focusedCommentId=21428&page=com.atlassian.jira.plugin.system.issuetabpanels%3Acomment-tabpanel#comment-21428> a while back and mean initialization time with a 40 node cluster with auth was ~251ms). Have you tried executing several trials of Cluster.connect within a single JVM process, does the initialization time improve with a subsequent Cluster.connect? I'm wondering if maybe there is some additional first-time initialization required that was not before. Thanks, Andy On Mon, Mar 6, 2017 at 6:01 AM, Matija Gobec <matija0...@gmail.com> wrote: > Interesting question since I never measured connect and close times. > Usually this is something you do once the application starts and thats it. > Do you plan to misuse it and create a new cluster object and open a new > connection for each request? > > On Mon, Mar 6, 2017 at 7:19 AM, Satoshi Hikida <sahik...@gmail.com> wrote: > >> Hi, >> >> I'm going to try to update the DataStax's Java Driver version from 2.1.8 >> to 3.1.3. >> First I ran the test program and measured the time with both drivers >> v2.1.8 and v3.1.3. >> >> The test program is simply Build a Cluster and connect to it and execute >> a simple select statement, and close the Cluster. >> >> The read performance was almost the same for both version (around 20ms), >> However, the performance of connecting to the cluster, and closing the >> cluster were significant different. >> >> The test environment is as following: >> - EC2 instance: m4.large(2vCPU, 8GB Memory), 1 node >> - java1.8 >> - Cassandra v2.2.8 >> >> Here is the result of the test. I ran the test program for several times >> but the result almost the same as this result. >> >> | Method | Time in sec (v2.1.8/v3.1.3)| >> |-----------------------|------------------------------------| >> | Cluster#connect | 1.178/2.468 | >> | Cluster#close | 0.022/2.240 | >> >> With v3.1.3 driver, Cluster#connect() performance degraded about 1/2 and >> Cluster#close() degraded 1/100. I want to know what is the cause of this >> performance degradations. Could someone advice me? >> >> >> The Snippet of the test program is as following. >> ``` >> Cluster cluster = Cluster >> .builder() >> .addContactPoints(endpoints) >> .withCredentials(USER, PASS) >> .withClusterName(CLUSTER_NAME) >> .withRetryPolicy(DefaultRetryPolicy.INSTANCE) >> // .withLoadBalancingPolicy(new TokenAwarePolicy(new >> DCAwareRoundRobinPolicy(DC_NAME))) // for driver 2.1.8 >> .withLoadBalancingPolicy(new >> TokenAwarePolicy(DCAwareRoundRobinPolicy.builder().build())) >> // for driver 3.1.3 >> .build(); >> >> Session session = cluster.connect(); >> ResultSet rs = session.execute("select * from system.local;"); >> >> session.close(); >> cluster.close(); >> ``` >> >> Regards, >> Satoshi >> >> >
