Hi André, First about network. Client and server are in the same segment and there are no firewalls in between them. Second I expect connection to be alive because during initiation I specify 'keep-alive' property of HTTP request. Also Tomcat and WLS are configured to support keepalive connections.
From what I noticed, I monitored TCP connection using TCPView and Wireshark (on the client side), TCP connection is still alive even Tomcat or WLS cannot write to the socket. Just to mention, I have in my code an option to send periodical heartbeats to the client if there is no data. It is configurable and when I use this option everything works fine. But if I don’t send heartbeats as I wrote before connection becomes stale and I want to understand why it happens so that I can initiate, for example, automatic client logoff and cleanup resources. On 29/01/16 11:33, "André Warnier (tomcat)" <a...@ice-sa.com> wrote: >On 28.01.2016 18:38, Maxim Neshcheret wrote: >> I have a problem with my java application related to HTTP communication. >> >> Application description: >> >> 1. Client – server. Server is running in servlet container. We use >>Tomcat. >> >> Client use java HTTP library to communicate with the server. >> >> 2. When client establish connection to the server it sends GET >>request (keepalive) and server creates AsyncContext for the client with >>10 days timeout. >> >> 3. After connection established server periodically sends data to >>the client using AsyncContext and on the client side there is special >>thread which reads and processes the data. >> >[ snip ...] >> >> Usually this code works fine but it there is no data from server to >>client for 1 day and after 24 hours (can be 16 or 12) data appears, >>server cannot send data to the client. >> In the log there is no error. It is written that everything flushed but >>client still waiting for data in “final String line = reader.readLine();” >> When 2nd portion of data is sent by the server, then during flush I see >>the following error >> >> 2016-01-26 00:00:00,051|INFO |GWNotify-2/50 |ClientAbort >> 2016-01-26 00:00:00,051|TRACE|GWNotify-2/50 >>|ClientAbortException:java.io.IOException: APR error: -32 >> org.apache.catalina.connector.ClientAbortException: >>java.io.IOException: APR error: -32 >[snip ...] > >Hi. >I am unqualified to check your code, but a first question would be : >where is the Client, >and where is the Server and what is the connection between them like ? > >And the reason for the question is : it is not at all unusual, that any >kind of network >connection would be interrupted at some point over a 24-hour period, >specially if nothing >is sent over that connection for a long time. >When a connection "disappears", TCP sends no signal to either the client >or the server, >and an error will only be caught, if one of the parties tries to write to >the (now gone) >connection (which seems to be what happens above, when the server tries >to write to the >Client, and gets a "client is no longer there" exception). > >If you want to avoid this, you will have to handle this in your code. >You cannot just >expect the connection to be alive no matter what. > > > > >--------------------------------------------------------------------- >To unsubscribe, e-mail: users-unsubscr...@tomcat.apache.org >For additional commands, e-mail: users-h...@tomcat.apache.org >
