[jira] Commented: (LUCENE-1472) DateTools.stringToDate() can cause lock contention under load
[ https://issues.apache.org/jira/browse/LUCENE-1472?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=12673771#action_12673771 ] Mark Lassau commented on LUCENE-1472: - An update for anyone interested: The test run that showed this contention suffered even worse contention in another component of our application. Since we have fixed that component, we have no longer observed contention in DateTools.stringToDate(). For that reason, this issue is not now considered a priority for us. > DateTools.stringToDate() can cause lock contention under load > - > > Key: LUCENE-1472 > URL: https://issues.apache.org/jira/browse/LUCENE-1472 > Project: Lucene - Java > Issue Type: Improvement > Components: Search >Affects Versions: 2.3.2 >Reporter: Mark Lassau >Priority: Minor > Fix For: 2.9 > > > Load testing our application (the JIRA Issue Tracker) has shown that threads > spend a lot of time blocked in DateTools.stringToDate(). > The stringToDate() method uses a singleton SimpleDateFormat object to parse > the dates. > Each call to SimpleDateFormat.parse() is *synchronized* because > SimpleDateFormat is not thread safe. -- This message is automatically generated by JIRA. - You can reply to this email to add a comment to the issue online. - To unsubscribe, e-mail: java-dev-unsubscr...@lucene.apache.org For additional commands, e-mail: java-dev-h...@lucene.apache.org
[jira] Commented: (LUCENE-1472) DateTools.stringToDate() can cause lock contention under load
[ https://issues.apache.org/jira/browse/LUCENE-1472?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=12652336#action_12652336 ] Michael McCandless commented on LUCENE-1472: I agree: ThreadLocal, despite its problems, is probably the best solution here. The memory cost ought to be tiny. We could also use CloseableThreadLocal (which works around the problems of ThreadLocal), and then allow DateTools to be instantiated, and add a close() method to it (vs the all-static methods we have today). This way the application could close the DateTools instance and reliably free up the tiny amount of memory used. > DateTools.stringToDate() can cause lock contention under load > - > > Key: LUCENE-1472 > URL: https://issues.apache.org/jira/browse/LUCENE-1472 > Project: Lucene - Java > Issue Type: Improvement > Components: Search >Affects Versions: 2.3.2 >Reporter: Mark Lassau >Priority: Minor > > Load testing our application (the JIRA Issue Tracker) has shown that threads > spend a lot of time blocked in DateTools.stringToDate(). > The stringToDate() method uses a singleton SimpleDateFormat object to parse > the dates. > Each call to SimpleDateFormat.parse() is *synchronized* because > SimpleDateFormat is not thread safe. -- This message is automatically generated by JIRA. - You can reply to this email to add a comment to the issue online. - To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
[jira] Commented: (LUCENE-1472) DateTools.stringToDate() can cause lock contention under load
[ https://issues.apache.org/jira/browse/LUCENE-1472?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=12652221#action_12652221 ] robert engels commented on LUCENE-1472: --- The last comment was tested using Java 5. It is my understanding that in Java 6, synchronization has become even cheaper - although object creation is cheaper as well - although 99% of the instantiation time of SimpleDateFormat is in the init code, not the object creation. I know there has been a lot of discussion of the "problems" with ThreadLocals... I've been a part of most of them :) - but for these very small objects, the typical ThreadLocal memory issues don't really apply. > DateTools.stringToDate() can cause lock contention under load > - > > Key: LUCENE-1472 > URL: https://issues.apache.org/jira/browse/LUCENE-1472 > Project: Lucene - Java > Issue Type: Improvement > Components: Search >Affects Versions: 2.3.2 >Reporter: Mark Lassau >Priority: Minor > > Load testing our application (the JIRA Issue Tracker) has shown that threads > spend a lot of time blocked in DateTools.stringToDate(). > The stringToDate() method uses a singleton SimpleDateFormat object to parse > the dates. > Each call to SimpleDateFormat.parse() is *synchronized* because > SimpleDateFormat is not thread safe. -- This message is automatically generated by JIRA. - You can reply to this email to add a comment to the issue online. - To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
[jira] Commented: (LUCENE-1472) DateTools.stringToDate() can cause lock contention under load
[ https://issues.apache.org/jira/browse/LUCENE-1472?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=12652220#action_12652220 ] robert engels commented on LUCENE-1472: --- If you review the source for SimpleDateFormat you will see that it internally performs some synchronization during initialization anyway (uses some Hashtables), and also that the initialization cost is pretty high (lots of code), so a static sync'd copy is probably best. Outside of that, the ThreadLocal is the way to go. My tests shows that the instantiation time is 2x longer than the typical parse time. > DateTools.stringToDate() can cause lock contention under load > - > > Key: LUCENE-1472 > URL: https://issues.apache.org/jira/browse/LUCENE-1472 > Project: Lucene - Java > Issue Type: Improvement > Components: Search >Affects Versions: 2.3.2 >Reporter: Mark Lassau >Priority: Minor > > Load testing our application (the JIRA Issue Tracker) has shown that threads > spend a lot of time blocked in DateTools.stringToDate(). > The stringToDate() method uses a singleton SimpleDateFormat object to parse > the dates. > Each call to SimpleDateFormat.parse() is *synchronized* because > SimpleDateFormat is not thread safe. -- This message is automatically generated by JIRA. - You can reply to this email to add a comment to the issue online. - To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
[jira] Commented: (LUCENE-1472) DateTools.stringToDate() can cause lock contention under load
[ https://issues.apache.org/jira/browse/LUCENE-1472?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=12652206#action_12652206 ] Mark Lassau commented on LUCENE-1472: - My original thought was ThreadLocal, but I tend to try and avoid these where possible. I wanted to test the speed on creating a new Calendar (rather than SimpleDateFormat) for each request, but was worried about the instantiation overhead. Daniel's comment above reinforces this concern to some extent, so we'll have to wait and compare benchmarks. > DateTools.stringToDate() can cause lock contention under load > - > > Key: LUCENE-1472 > URL: https://issues.apache.org/jira/browse/LUCENE-1472 > Project: Lucene - Java > Issue Type: Improvement > Components: Search >Affects Versions: 2.3.2 >Reporter: Mark Lassau >Priority: Minor > > Load testing our application (the JIRA Issue Tracker) has shown that threads > spend a lot of time blocked in DateTools.stringToDate(). > The stringToDate() method uses a singleton SimpleDateFormat object to parse > the dates. > Each call to SimpleDateFormat.parse() is *synchronized* because > SimpleDateFormat is not thread safe. -- This message is automatically generated by JIRA. - You can reply to this email to add a comment to the issue online. - To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
[jira] Commented: (LUCENE-1472) DateTools.stringToDate() can cause lock contention under load
[ https://issues.apache.org/jira/browse/LUCENE-1472?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=12652194#action_12652194 ] Doug Cutting commented on LUCENE-1472: -- ThreadLocal? > DateTools.stringToDate() can cause lock contention under load > - > > Key: LUCENE-1472 > URL: https://issues.apache.org/jira/browse/LUCENE-1472 > Project: Lucene - Java > Issue Type: Improvement > Components: Search >Affects Versions: 2.3.2 >Reporter: Mark Lassau >Priority: Minor > > Load testing our application (the JIRA Issue Tracker) has shown that threads > spend a lot of time blocked in DateTools.stringToDate(). > The stringToDate() method uses a singleton SimpleDateFormat object to parse > the dates. > Each call to SimpleDateFormat.parse() is *synchronized* because > SimpleDateFormat is not thread safe. -- This message is automatically generated by JIRA. - You can reply to this email to add a comment to the issue online. - To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
[jira] Commented: (LUCENE-1472) DateTools.stringToDate() can cause lock contention under load
[ https://issues.apache.org/jira/browse/LUCENE-1472?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=12652085#action_12652085 ] Daniel Naber commented on LUCENE-1472: -- Could you try changing the code to create a new object every time and then run your load test again? We original did that but it was slower, at least according to this commit comment from two years ago: "Don't re-create SimpleDateFormat objects, use static ones instead. Gives about a 2x performance increase in a micro benchmark." > DateTools.stringToDate() can cause lock contention under load > - > > Key: LUCENE-1472 > URL: https://issues.apache.org/jira/browse/LUCENE-1472 > Project: Lucene - Java > Issue Type: Improvement > Components: Search >Affects Versions: 2.3.2 >Reporter: Mark Lassau >Priority: Minor > > Load testing our application (the JIRA Issue Tracker) has shown that threads > spend a lot of time blocked in DateTools.stringToDate(). > The stringToDate() method uses a singleton SimpleDateFormat object to parse > the dates. > Each call to SimpleDateFormat.parse() is *synchronized* because > SimpleDateFormat is not thread safe. -- This message is automatically generated by JIRA. - You can reply to this email to add a comment to the issue online. - To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
[jira] Commented: (LUCENE-1472) DateTools.stringToDate() can cause lock contention under load
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https://issues.apache.org/jira/browse/LUCENE-1472?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=12651900#action_12651900
]
Mark Lassau commented on LUCENE-1472:
-
[SimpleDateFormat
javadoc|http://java.sun.com/javase/6/docs/api/java/text/SimpleDateFormat.html]:
{quote}
Date formats are not synchronized.
It is recommended to create separate format instances for each thread.
If multiple threads access a format concurrently, it must be synchronized
externally.
{quote}
> DateTools.stringToDate() can cause lock contention under load
> -
>
> Key: LUCENE-1472
> URL: https://issues.apache.org/jira/browse/LUCENE-1472
> Project: Lucene - Java
> Issue Type: Improvement
> Components: Search
>Affects Versions: 2.3.2
>Reporter: Mark Lassau
>Priority: Minor
>
> Load testing our application (the JIRA Issue Tracker) has shown that threads
> spend a lot of time blocked in DateTools.stringToDate().
> The stringToDate() method uses a singleton SimpleDateFormat object to parse
> the dates.
> Each call to parse is *synchronized* because SimpleDateFormat is not thread
> safe.
--
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[jira] Commented: (LUCENE-1472) DateTools.stringToDate() can cause lock contention under load
[ https://issues.apache.org/jira/browse/LUCENE-1472?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=12651899#action_12651899 ] Mark Lassau commented on LUCENE-1472: - The following methods would potentially suffer contention as well depending on usage patterns of the particular app: * stringToTime() * dateToString() * timeToString() > DateTools.stringToDate() can cause lock contention under load > - > > Key: LUCENE-1472 > URL: https://issues.apache.org/jira/browse/LUCENE-1472 > Project: Lucene - Java > Issue Type: Improvement > Components: Search >Affects Versions: 2.3.2 >Reporter: Mark Lassau >Priority: Minor > > Load testing our application (the JIRA Issue Tracker) has shown that threads > spend a lot of time blocked in DateTools.stringToDate(). > The stringToDate() method uses a singleton SimpleDateFormat object to parse > the dates. > Each call to parse is *synchronized* because SimpleDateFormat is not thread > safe. -- This message is automatically generated by JIRA. - You can reply to this email to add a comment to the issue online. - To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
