Jetty

Jetty won't serve requests if the number of connector threads is too big (regression).

Details

  • Type: Bug Bug
  • Status: Resolved Resolved
  • Priority: Minor Minor
  • Resolution: Fixed
  • Affects Version/s: 7.0.0.pre5, 6.1.12
  • Fix Version/s: 7.0.0.pre5, 6.1.12
  • Component/s: None
  • Labels:
    None
  • Environment:
    C:\>java -version
    java version "1.6.0_10-rc"
    Java(TM) SE Runtime Environment (build 1.6.0_10-rc-b28)
    Java HotSpot(TM) Client VM (build 11.0-b15, mixed mode, sharing)
  • Number of attachments :
    0

Description

The following code:
AbstractConnector connector = new SelectChannelConnector();
connector.setAcceptors(30);
server.addConnector(connector);
worked with Jetty 6.1.6, but won't work with recent versions of Jetty (long pause followed by an empty page instead of a correctly served page).
Switching to SocketConnector wouldn't help.
What helps, though, is decreasing the number of acceptors to 20 or doing
server.setThreadPool(new QueuedThreadPool(40));

It seems that in the newer version of Jetty the pool is shared, but the connector starts all the threads beforehand and so the pool is depleted.
1. It is regression - old code which worked okey now doesn't works.
2. There is no diagnostics: no log messages or anything, the problem is hard to find.

Activity

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Artem Kozarezov added a comment -

BTW, a question: is it really necessary to start all the threads beforehand?
I now have a server where I have to set the number of threads to 90, just to be safe, but the real amount used might be less than 10.
If it is possible not to prestart all the threads, then how can it be achieved?
Thanks.

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Artem Kozarezov added a comment - BTW, a question: is it really necessary to start all the threads beforehand? I now have a server where I have to set the number of threads to 90, just to be safe, but the real amount used might be less than 10. If it is possible not to prestart all the threads, then how can it be achieved? Thanks.
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Greg Wilkins added a comment -

Artem,

Only min threads are created before hand. Max threads are only created on demand.

Note that there should be no reason to set acceptors to such a high value, but then Jetty should
give error messages if it has run out of threads while creating acceptors. We will investigate the
regression.

cheers

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Greg Wilkins added a comment - Artem, Only min threads are created before hand. Max threads are only created on demand. Note that there should be no reason to set acceptors to such a high value, but then Jetty should give error messages if it has run out of threads while creating acceptors. We will investigate the regression. cheers
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Greg Wilkins added a comment -

For the current releases, I've just increased the default max size to 250, but will leave this open to do a better error message for the next release.

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Greg Wilkins added a comment - For the current releases, I've just increased the default max size to 250, but will leave this open to do a better error message for the next release.
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Artem Kozarezov added a comment -

??Artem,
Only min threads are created before hand. Max threads are only created on demand.??

Perhaps the thread pool itself behaves as you say, but in the connector(s) I see no "setMaxAcceptors" or "setMinAcceptors" method, only the "setAcceptors" method, and the problem is that the connector(s) allocates all these threads beforehand (even until it reaches the thread pool maximum).

Note that there should be no reason to set acceptors to such a high value

That depends on the application.

Show
Artem Kozarezov added a comment - ??Artem, Only min threads are created before hand. Max threads are only created on demand.?? Perhaps the thread pool itself behaves as you say, but in the connector(s) I see no "setMaxAcceptors" or "setMinAcceptors" method, only the "setAcceptors" method, and the problem is that the connector(s) allocates all these threads beforehand (even until it reaches the thread pool maximum). Note that there should be no reason to set acceptors to such a high value That depends on the application.
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David Yu added a comment -

marking as resolved ... covered by jetty-6.1.12 & 7.0.0.pre5 release

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David Yu added a comment - marking as resolved ... covered by jetty-6.1.12 & 7.0.0.pre5 release

People

  • Assignee:
    Unassigned
    Reporter:
    Artem Kozarezov
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Dates

  • Created:
    Updated:
    Resolved: