Occasional exception: org.jredis.connector.ConnectionReset: Connection re-established but last request not processed: in.read returned -1

[subwiz]

This is the trace:

[11-09-16 18:56:25.016] {http://*:8080-18} org.jredis.connector.ConnectionReset: Connection re-established but last request not processed:  in.read returned -1
                                                at org.jredis.ri.alphazero.connection.SyncConnection.serviceRequest(SyncConnection.java:138)
                                                at org.jredis.ri.alphazero.JRedisClient.serviceRequest(JRedisClient.java:151)
                                                at org.jredis.ri.alphazero.JRedisSupport.lrange(JRedisSupport.java:1218)
                                                at in.fileit.fileitin.OpPost.getKeyPosts(OpPost.java:360)
                                                at in.fileit.fileitin.OpPost.getPosts(OpPost.java:408)
                                                at in.fileit.fileitin.ServletIndex.doGet(ServletIndex.java:26)
                                                at javax.servlet.http.HttpServlet.service(HttpServlet.java:119)
                                                at javax.servlet.http.HttpServlet.service(HttpServlet.java:96)
                                                at com.caucho.server.dispatch.ServletFilterChain.doFilter(ServletFilterChain.java:109)
                                                at in.fileit.fileitin.FilterDataSource.doFilter(FilterDataSource.java:58)
                                                at com.caucho.server.dispatch.FilterFilterChain.doFilter(FilterFilterChain.java:89)
                                                at com.caucho.server.webapp.WebAppFilterChain.doFilter(WebAppFilterChain.java:156)
                                                at com.caucho.server.webapp.AccessLogFilterChain.doFilter(AccessLogFilterChain.java:95)
                                                at com.caucho.server.dispatch.ServletInvocation.service(ServletInvocation.java:287)
                                                at com.caucho.server.http.HttpRequest.handleRequest(HttpRequest.java:811)
                                                at com.caucho.network.listen.TcpSocketLink.dispatchRequest(TcpSocketLink.java:1186)
                                                at com.caucho.network.listen.TcpSocketLink.handleRequest(TcpSocketLink.java:1148)
                                                at com.caucho.network.listen.TcpSocketLink.handleRequestsImpl(TcpSocketLink.java:1132)
                                                at com.caucho.network.listen.TcpSocketLink.handleRequests(TcpSocketLink.java:1055)
                                                at com.caucho.network.listen.TcpSocketLink.handleAcceptTask(TcpSocketLink.java:903)
                                                at com.caucho.network.listen.AcceptTask.doTask(AcceptTask.java:74)
                                                at com.caucho.network.listen.ConnectionTask.runThread(ConnectionTask.java:97)
                                                at com.caucho.network.listen.ConnectionTask.run(ConnectionTask.java:80)
                                                at com.caucho.network.listen.AcceptTask.run(AcceptTask.java:59)
                                                at com.caucho.env.thread.ResinThread.runTasks(ResinThread.java:164)
                                                at com.caucho.env.thread.ResinThread.run(ResinThread.java:130)

This is happening on random basis. I am using the latest jredis from trunk ( 2c58286 ) and using Redis 2.2.12.

[alphazero]

That's due to a connection timeout. Java does not raise an error on a dropped connection on send and it's only on the read end that you get a -1 returned (with semantics as defined in the javadocs e.g. "connection reset"). What is the timeout value in redis conf?

[subwiz]

It is set at 300 seconds in redis.conf.

This could also be due to the way I implemented Connection management---using ThreadLocal. So I will verify if there are any connections open in my side for more than 300 seconds.

Thanks for the pointer.

[alphazero]

NP; happy to help. I assumed you were pooling connections; can you confirm?

[subwiz]

I was believing that I have to manually pool connections..., so I implemented my logic based on a Servlet Filter which creates a new Redis connection, and throughout this particular request flow, this connection is used. Is there a better approach for pooling connections?

[alphazero]

hmm. If you have a connection per request, then why would it even be idle for > 300s ??

[subwiz]

I have to run some test if my implementation of ThreadLocal is holding connections open. So do you know of any OpenSource connection pool library for JRedis?

[subwiz]

I added few logs to my application and see that it is indeed timeout problem. Now I have pointer to work on this issue independently. I am closing this issue because this is not a JRedis bug.

Thanks a lot for the pointer.

[alphazero]

Reopening as documentation issue.

[alphazero]

Closing this. The javadoc for the exception states explicitly this is "typically due to timeout on Redis side".

[subwiz]

Can this also be added as part of Exception message?