Hello all, I am using mina 2.0.8 since I needed a patch included in this release.
I face the following problem: The concept of the application is to "multiplex" inbound to outbound connections in MINA. This means that there might be 2 incoming connections that are multiplexed in one outbound connection. During my tests i randomly see this exception: java.nio.InvalidMarkException at java.nio.Buffer.reset(Buffer.java:298) ~[?:1.7.0_40] at org.apache.mina.core.buffer.AbstractIoBuffer.reset(AbstractIoBuffer.java:414) ~[mina-core-2.0.8-PATCHED.jar:?] at org.apache.mina.core.polling.AbstractPollingIoProcessor.writeBuffer(AbstractPollingIoProcessor.java:926) ~[mina-core-2.0.8-SNAPSHOT.jar:?] at org.apache.mina.core.polling.AbstractPollingIoProcessor.flushNow(AbstractPollingIoProcessor.java:844) [mina-core-2.0.8-SNAPSHOT.jar:?] at org.apache.mina.core.polling.AbstractPollingIoProcessor.flush(AbstractPollingIoProcessor.java:772) [mina-core-2.0.8-SNAPSHOT.jar:?] at org.apache.mina.core.polling.AbstractPollingIoProcessor.access$700(AbstractPollingIoProcessor.java:67) [mina-core-2.0.8-SNAPSHOT.jar:?] at org.apache.mina.core.polling.AbstractPollingIoProcessor$Processor.run(AbstractPollingIoProcessor.java:1112) [mina-core-2.0.8-SNAPSHOT.jar:?] at org.apache.mina.util.NamePreservingRunnable.run(NamePreservingRunnable.java:64) [mina-core-2.0.8-SNAPSHOT.jar:?] at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145) [?:1.7.0_40] at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615) [?:1.7.0_40] at java.lang.Thread.run(Thread.java:724) [?:1.7.0_40] After some investigation i noticed that this happened when 2 threads decided to write to the same IoSession a message the same time. My assumption is that the #IoSession.write method is not thread safe, thus i synchronized the session instance before executing the write method in my handlers and up until now i haven't faced the same issue. Is my assumption valid? Thank you in advance, Alex