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Static methods in concurrency

811242Feb 10 2011 — edited Feb 10 2011
I have a static method which takes a few String and double parameters and contains only local variables. When it is called by multiple threads there seems to be an exception thrown intermittenly. I got a little paranoid and so I've changed it to an instance method, and now the problem seems to disappear.

Is this just a coincidence? Is my static method intrinsically thread-safe? Or are there any concurrency issues with static methods that I'm not aware of?

Any reply is much appreciated!

Comments

795934
Rolf_Gitt wrote:
I have a Sun 6140 SAN that is apparently having a NIC flapping problem (according to our network team) on the Controller B IP connection - which is causing network problems on the entire subnet. Controller A connection is working fine.
I don't have any direct experience, but a [previous thread|http://forums.sun.com/thread.jspa?forumID=831&threadID=5342251] pointed to the following Sun Alert which is the cause of the "flapping problem":
[Sun StorageTek 25x0 and 6140 Arrays may send wrong Network packets, causing the Sun StorageTek Common Array Manager (CAM) Host to Lose the Network Connection to the Array|http://sunsolve.sun.com/search/document.do?assetkey=1-66-240105-1]

Looks like a firmware upgrade will fix the flapping problem.
807557
hi Rolf_Gitt
So - my question is: Can I unplug the Controller B NIC for a few days without any significant consequences for end user data access or SAN control, assuming Controller A NIC works fine?
Yes you can unplug the ethernet from controller B without any significant consequences. Just remember that if you do a firmware upgrade to plug it back in again otherwise the process will fail.

David
807557
Thanks for pointing out the issue! That is most helpful.

I'll assign some "Duke stars" once I figure out how to do that!
797527
Rolf_Gitt wrote:
So - my question is: Can I unplug the Controller B NIC for a few days without any significant consequences for end user data access or SAN control, assuming Controller A NIC works fine?
Not without consequence. If you do that, you will trigger the following problems:

1. CAM will report alarms due to the communication lost with controller B.
2. If you engage us (Sun support), we won't be in position to assist you efficiently because the supportdata you will collect will miss the controller B information for one particular file.
3. F/W upgrade won't be possible while one controller only is attached to the network.

Therefore, instead of unplugging the controller B network interface, I would suggest you to contact your local Sun support team and work with them in order to narrow down this issue by using different methods.

Regards
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Locked on Mar 10 2011
Added on Feb 10 2011
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