|
Problem IT30967
|
Status: Closed |
DRIVER CAN DEADLOCK WHEN CLOSING LARGE OBJECT INPUT STREAM WHILEEXECUTING STATEMENTS IN PARALLEL
|
| product: |
IBM JDBC / 5724I3501 / 410 - Informix 4.10 |
| Problem description: |
Both getGeneratedCursor and IfxLobInputStream.close() lock on
ifxSqliConnect (the connection).
When ran in parallel they can enter a deadlock condition with
the underlying SQLI protocol lock
which is used for fastpath execution (used for closing the lob)
as well as for normal statement execution.
Thread Dump below:
"ajp-nio-8009-exec-25" - Thread t@156044
java.lang.Thread.State: BLOCKED
at
com.informix.jdbc.IfxSqliConnect.getGeneratedCursor(IfxSqliConne
ct.java:4179)
- waiting to lock (a
com.informix.jdbc.IfxSqliConnect) owned by
"ajp-nio-8009-exec-21" t@156021
- locked (a com.informix.jdbc.IfxSqliConnect)
at
com.informix.jdbc.IfxStatement.getGeneratedCursor(IfxStatement.j
ava:898)
at
com.informix.jdbc.IfxStatement.getCursorName(IfxStatement.java:8
83)
at
com.informix.jdbc.IfxSqli.sendQuery(IfxSqli.java:1688)
at
com.informix.jdbc.IfxSqli.sendStatementQuery(IfxSqli.java:1521)
at
com.informix.jdbc.IfxSqli.executeStatementQuery(IfxSqli.java:150
0)
"ajp-nio-8009-exec-21" - Thread t@156021
java.lang.Thread.State: WAITING
at sun.misc.Unsafe.park(Native Method)
- waiting to lock (a
java.util.concurrent.locks.ReentrantLock$NonfairSync) owned by
"ajp-nio-8009-exec-25" t@156044
at
java.util.concurrent.locks.LockSupport.park(LockSupport.java:186
)
at
java.util.concurrent.locks.AbstractQueuedSynchronizer.parkAndChe
ckInterrupt(AbstractQueuedSynchronizer.java:847)
at
java.util.concurrent.locks.AbstractQueuedSynchronizer.acquireQue
ued(AbstractQueuedSynchronizer.java:881)
at
java.util.concurrent.locks.AbstractQueuedSynchronizer.acquire(Ab
stractQueuedSynchronizer.java:1210)
at
java.util.concurrent.locks.ReentrantLock$NonfairSync.lock(Reentr
antLock.java:220)
at
java.util.concurrent.locks.ReentrantLock.lock(ReentrantLock.java
:296)
at
com.informix.jdbc.IfxSqliConnect.lockSession(IfxSqliConnect.java
:4120)
at
com.informix.jdbc.IfxSqli.executeFastPath(IfxSqli.java:5080)
at
com.informix.jdbc.IfxSqli.executeFastPath(IfxSqli.java:5038)
at
com.informix.jdbc.IfxSmartBlob.IfxLoRelease(IfxSmartBlob.java:53
9)
at
com.informix.jdbc.IfxLobInputStream.close(IfxLobInputStream.java
:243)
- locked (a com.informix.jdbc.IfxSqliConnect)
at
java.io.BufferedInputStream.close(BufferedInputStream.java:494)
at
com.halo.portal.servlet.ThumbnailServlet.doGet(ThumbnailServlet.
java:86) |
| Problem Summary: |
****************************************************************
* USERS AFFECTED: *
* Users of Informix JDBC versions prior to 4.50.JC3. *
****************************************************************
* PROBLEM DESCRIPTION: *
* Both getGeneratedCursor and IfxLobInputStream.close() lock *
* on *
* ifxSqliConnect (the connection). *
* When ran in parallel they can enter a deadlock condition *
* with *
* the underlying SQLI protocol lock *
* which is used for fastpath execution (used for closing the *
* lob) *
* as well as for normal statement execution. *
****************************************************************
* RECOMMENDATION: *
**************************************************************** |
| Local Fix: |
|
| Solution |
|
| Workaround |
****************************************************************
* USERS AFFECTED: *
* Users of Informix JDBC versions prior to 4.50.JC3. *
****************************************************************
* PROBLEM DESCRIPTION: *
* Both getGeneratedCursor and IfxLobInputStream.close() lock *
* on *
* ifxSqliConnect (the connection). *
* When ran in parallel they can enter a deadlock condition *
* with *
* the underlying SQLI protocol lock *
* which is used for fastpath execution (used for closing the *
* lob) *
* as well as for normal statement execution. *
****************************************************************
* RECOMMENDATION: *
**************************************************************** |
| Comment |
Fixed in Informix JDBC version 4.50.JC4. |
| Timestamps |
Date - problem reported :
Date - problem closed :
Date - last modified :
| 15.11.2019
15.11.2019
18.12.2019 |
| Problem solved at the following versions (IBM BugInfos) |
4.50.JC4
|
| Problem solved according to the fixlist(s) of the following version(s) |
