[#DIRSERVER-1019] Using same thread pool for I/O processing and request handling causes clients to hang and MINA thread pool depletion

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Using same thread pool for I/O processing and request handling causes clients to hang and MINA thread pool depletion

Created: 16/Aug/07 06:35 AM Updated: 16/Aug/07 07:14 PM

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Component/s:

None

Affects Version/s:

1.5.0, 1.0.2, 1.0.1, 1.0, 1.0-RC4, 1.0-RC3, 1.0-RC2, 1.0-RC1, pre-1.0

Fix Version/s:

1.5.1, 1.0.3

Time Tracking:

Not Specified

Resolution Date:

16/Aug/07 07:14 PM

Description

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In the ServerContext factory the same thread pool is being used to process I/O
and request handling. This is depleting the thread pool rapidly causing the
server to hang under certain conditions. I caught this bug on a x86_64 machine
with multiple cores when the ReferralITest test was hanging. The right number
of connections and requests being processed could have caused this issue to
arrise. Regardless thankfully the issue appeared and Trustin found the cause
for it.

Trustin tracked the bug down to the way we misconfigured MINA's thread pools.
He is currently fixing the problem in trunk and I suspect the same issue exists
within the 1.0 branch.

I suspect this could have caused serious issues in performance if not causing
several load test clients to hang while others had requests processed. I
recommend reassessing performance metrics once again after this fix. There
should be a considerable boost. I think our impression that MINA was a
bottleneck may have been attributed to this misconfiguration issue.

Anyways once Trustin has the fix in trunk I will apply it to the 1.0 branch and
make sure all tests pass successfully. I am assigning this issue to myself
even though T is providing the fix so I can manage the application on the
1.0 branch and document the results.

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Alex Karasulu added a comment - 16/Aug/07 06:37 AM

Improving title for clarity

Alex Karasulu made changes - 16/Aug/07 06:37 AM

Field	Original Value	New Value
Summary	Using same thread pool for I/O processing as request handling	Using same thread pool for I/O processing and request handling causes clients to hang and MINA thread pool depletion

Alex Karasulu made changes - 16/Aug/07 06:41 AM

Status

Open [ 1 ]

In Progress [ 3 ]

Repository	Revision	Date	User	Message
ASF	#566769	Thu Aug 16 16:36:38 UTC 2007	akarasulu	Fixed bug arrising from corrections made to fix ~~DIRSERVER-1019~~ ... Seems as though the fixes for this revealed an inconsistent state that occurs in the poorly written filter parser. I have created another JIRA to rewrite the filter parser here: https://issues.apache.org/jira/browse/DIRSERVER-1020 Anyways I found a work around which hides the symptoms instead of curring this disease. The cure is a parser rewrite in the nice way that seelmann did it for the other parsers. The work around I used was to make the filter parser in the ServerDirContext implementation a instance member instead of a static class member. Again this just hides the issue rather than fixing it.
				Files Changed
				MODIFY /directory/apacheds/trunk/server-unit/src/test/java/org/apache/directory/server/PersistentSearchTest.java MODIFY /directory/apacheds/trunk/core/src/main/java/org/apache/directory/server/core/configuration/StartupConfiguration.java MODIFY /directory/apacheds/trunk/server-jndi/src/main/java/org/apache/directory/server/jndi/ServerContextFactory.java MODIFY /directory/apacheds/trunk/core/src/main/java/org/apache/directory/server/core/jndi/ServerDirContext.java

Repository	Revision	Date	User	Message
ASF	#566796	Thu Aug 16 18:32:23 UTC 2007	akarasulu	fix for ~~DIRSERVER-1019~~ ... o fixed persistent search issues o using MINA properly with two pools now for logic and io o modified default for max number of threads to 32 as in trunk
				Files Changed
				MODIFY /directory/apacheds/branches/1.0/server-unit/src/test/java/org/apache/directory/server/PersistentSearchTest.java MODIFY /directory/apacheds/branches/1.0/server-jndi/src/main/java/org/apache/directory/server/jndi/ServerContextFactory.java MODIFY /directory/apacheds/branches/1.0/core/src/main/java/org/apache/directory/server/core/jndi/ServerDirContext.java MODIFY /directory/apacheds/branches/1.0/core/src/main/java/org/apache/directory/server/core/configuration/StartupConfiguration.java

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Alex Karasulu added a comment - 16/Aug/07 07:14 PM

This has been fixed thanks to Trustin.

Alex Karasulu made changes - 16/Aug/07 07:14 PM

Resolution		Fixed [ 1 ]
Status	In Progress [ 3 ]	Closed [ 6 ]