[Dspace-tech] Internal Server Error: Cannot get a connection, pool exhausted

[Damian Marinaccio]

We are experiencing this problem since going to 1.3.2...

Any ideas on this one?


Any help would be GREATLY appreciated.


Thanks,

Damian Marinaccio
RIT Libraries
dxm...@rit.edu
585-475-7741



-----Original Message-----
From: ritdml-...@rit.edu [mailto:ritdml-...@rit.edu]
Sent: Thursday, August 24, 2006 1:28 PM
To: Damian Marinaccio
Subject: RIT DML: Internal Server Error

An internal server error occurred on https://ritdml.rit.edu/dspace:

Date: 8/24/06 1:28 PM
Session ID: F09519183CB7D33F1C704B73D282E4FC

-- URL Was: http://athena.rit.edu:8080/dspace/handle/1850/1219
-- Method: GET
-- Parameters were:


Exception:
javax.servlet.ServletException: Cannot get a connection, pool exhausted
at
org.apache.jasper.runtime.PageContextImpl.handlePageException(PageContex
tImpl.java:536)
at
org.apache.jsp.collection_0002dhome_jsp._jspService(collection_0002dhome
_jsp.java:714)
at
org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:137)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:853)
at
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.ja
va:210)
at
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:295)
at
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:241)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:853)
at
org.apache.catalina.core.ApplicationDispatcher.invoke(ApplicationDispatc
her.java:684)
at
org.apache.catalina.core.ApplicationDispatcher.doForward(ApplicationDisp
atcher.java:432)
at
org.apache.catalina.core.ApplicationDispatcher.forward(ApplicationDispat
cher.java:356)
at
org.dspace.app.webui.util.JSPManager.showJSP(JSPManager.java:91)
at
org.dspace.app.webui.servlet.HandleServlet.collectionHome(HandleServlet.
java:503)
at
org.dspace.app.webui.servlet.HandleServlet.doDSGet(HandleServlet.java:19
2)
at
org.dspace.app.webui.servlet.DSpaceServlet.processRequest(DSpaceServlet.
java:151)
at
org.dspace.app.webui.servlet.DSpaceServlet.doGet(DSpaceServlet.java:99)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:740)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:853)
at
org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(Applica
tionFilterChain.java:247)
at
org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilt
erChain.java:193)
at
org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValv
e.java:256)
at
org.apache.catalina.core.StandardPipeline$StandardPipelineValveContext.i
nvokeNext(StandardPipeline.java:643)
at
org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:4
80)
at
org.apache.catalina.core.ContainerBase.invoke(ContainerBase.java:995)
at
org.apache.catalina.core.StandardContextValve.invoke(StandardContextValv
e.java:191)
at
org.apache.catalina.core.StandardPipeline$StandardPipelineValveContext.i
nvokeNext(StandardPipeline.java:643)
at
org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:4
80)
at
org.apache.catalina.core.ContainerBase.invoke(ContainerBase.java:995)
at
org.apache.catalina.core.StandardContext.invoke(StandardContext.java:241
7)
at
org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java
:180)
at
org.apache.catalina.core.StandardPipeline$StandardPipelineValveContext.i
nvokeNext(StandardPipeline.java:643)
at
org.apache.catalina.valves.ErrorDispatcherValve.invoke(ErrorDispatcherVa
lve.java:171)
at
org.apache.catalina.core.StandardPipeline$StandardPipelineValveContext.i
nvokeNext(StandardPipeline.java:641)
at
org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java
:172)
at
org.apache.catalina.core.StandardPipeline$StandardPipelineValveContext.i
nvokeNext(StandardPipeline.java:641)
at
org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:4
80)
at
org.apache.catalina.core.ContainerBase.invoke(ContainerBase.java:995)
at
org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.
java:174)
at
org.apache.catalina.core.StandardPipeline$StandardPipelineValveContext.i
nvokeNext(StandardPipeline.java:643)
at
org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:4
80)
at
org.apache.catalina.core.ContainerBase.invoke(ContainerBase.java:995)
at
org.apache.coyote.tomcat4.CoyoteAdapter.service(CoyoteAdapter.java:193)
at
org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:78
1)
at
org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.processC
onnection(Http11Protocol.java:549)
at
org.apache.tomcat.util.net.TcpWorkerThread.runIt(PoolTcpEndpoint.java:58
9)
at
org.apache.tomcat.util.threads.ThreadPool$ControlRunnable.run(ThreadPool
.java:666)
at java.lang.Thread.run(Thread.java:536)

[Jonathan Champ]

On 8/24/06, Damian Marinaccio <dxm...@rit.edu> wrote:
> We are experiencing this problem since going to 1.3.2...
>
> Any ideas on this one?

Sounds like high traffic problems. If this is the case, I have heard
upgrading Postgres, DSpace, Java, and Tomcat can help. Might want to
try that in the order that you feel safest with, probably Java,
Tomcat, Postgres, DSpace. Also, you seem to have been experience this
same problem when using 1.2.1
(http://sourceforge.net/mailarchive/message.php?msg_id=11254029). The
problem appears to be caused by too many connections left open
(http://forum.java.sun.com/thread.jspa?threadID=573335&tstart=120).
Looks like even Richard Jones noted this problem with that version
(http://sourceforge.net/mailarchive/message.php?msg_id=11572692). My
guess (if it's not a common problem these days) is that upgrading the
other pieces of software might be the solution. If other people are
still having a problem, and you have the memory available, you might
just consider increasing your connection count (as described in
Richard's e-mail).

Hope that helps!

Jonathan

[Tim Donohue]

Damian,

If this is happening frequently, you definitely should try and increase
your database connections available in the pool as Jonathan mentioned
(change db.maxconnections in the dspace.cfg).
However, if you do that, you may also want/need to give Postgres a
little more memory to work with. There's a few good performance tuning
tips on the DSpace Wiki:
http://wiki.dspace.org/HowToPerformanceTuneForDspace
http://wiki.dspace.org/PostgresPerformanceTuning

If this error looks to be more of a "one time occurrence", it's also
possible that it is a *very* unfriendly bot at work. I've had this
happen before where a "spam-bot" hit our site heavily for about 30-40
minutes straight and managed to use up all of the database connections
in our pool. I've since blocked that spam-bot (via its IP address),
and increased our connection pool size a little, and haven't seen those
problems since.

- Tim

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--

========================================
Tim Donohue
Research Programmer, Illinois Digital Environment for
Access to Learning and Scholarship (IDEALS)
52 Grainger Engineering Library
University of Illinois at Urbana-Champaign

email: tdon...@uiuc.edu
web: http://ideals.uiuc.edu
phone: (217) 244-7809
fax: (217) 244-7764
========================================