I noticed that the release notes for SwiftMQ 5.2.0 says that a bug is fixed in this release for "JMS Client: Connect request stuck (SMQPVersionRequest sent but no reply received). ", is anybody aware what is the symptom of this bug in 5.1.0? And how this has been fixed in version 5.2.0?
We are using 5.1.0, and one thing we observed was that some clients were not able to establish new connections to SwiftMQ (stucked), but the old existing connections were still working. And I am wondering whether this is due to the bug mentioned in the 5.2.0 release notes. Does anybody have idea on this?
Would appreciate your kind and prompt reply on this. Thanks!
The fix concerned thread synchronization during connect and protocol handshake in conjunction with the Java Memory Model. The bug didn't came up very often and it was not easy to reproduce it. Scenarios 2-6 describe it quite good.
However, it could also be a client problem (e.g. multithreaded access of a JMS session), a HP UX platform issue (in conjunction with 1.4.2) etc pp. To be absolutely sure, you should create a thread dump with kill -3 <pid> and submit an Incident. That way we can dig deeper in your problem, can verify your configuration and so on. This forum is only for basic questions, actually.
Thanks for the reply, and I really appreciate that! The problem is we cannot easily reproduce the symptom. And we purchased the s/w, and we want to make sure that by upgrading to the higher version, say from 5.1.0 to 5.2.0, this issue will be resolved.
Are you from SwiftMQ support? Can you advise me the contact or any ID can use for further assistance on this?
You should upgrade to the latest release (6.1.0) anyway. 5.1.0 is quite old and an upgrade to 5.2.0, also an old release, doesn't make sense. There are many bug fixes and improvements between 5.2.0 and 6.1.0.
The problem is, as you pointed out, that the connection stuck problem is not easily reproducible. Even when you catch it and produce a thread dump, you will only see idling threads. However, it was fixed in 5.2.0 and we didn't had any further problem reports concerning it. So that's fixed.
The easiest way is that you upgrade to 6.1.0 (clients and router) to have the latest release. We don't have any issues with 6.1.0 so it should work. However, if it appears that you still have problems then it's certainly a problem with your client. In that case I recommend that you open a support incident and refer to this forum thread. But only then. Upgrade first, please, and see whether it works.
Licenses are not bound to specific (major) releases. You can upgrade to the most current release free of charge if you are within maintenance. When you purchase a license, you will have 12 month free maintenance included. Thereafter you can renew maintenance year by year at 20% of the license fee.
Upgrading to 6.1.0 will not effect your apps. Upgrade the router by unpacking the 6.1.0 distro and use your 5.1.0routerconfig.xml on startup of 6.1.0. It will be converted during the first startup. To upgrade your JMS clients, simply replace the swiftmq.jar at your JMS client's classpath.
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One more question, since the latest version is 6.1.0, and if we have the support license, and we use the old version (e.g. 5.1.0, or 5.2.0), and encounter this issue, and we provide you with a dump using "kill -3", then question is that does SwiftMQ still support us even though it may be a quite old version? Support means:
1. Look into the dump and analyze it, and base on it to trouble shoot the JMS system;
2. Provide us with detail information whether this is a bug in JMS, and how to resolve it? And how to work around it using the current version?
Can you please help to clarify this at the earliest? Thanks a lot!
One more question, since the latest version is 6.1.0, and if we have the support license, and we use the old version (e.g. 5.1.0, or 5.2.0), and encounter this issue, and we provide you with a dump using "kill -3", then question is that does SwiftMQ still support us even though it may be a quite old version?