Re: Occasional deadlocking problems while connecting to IMAP server

> Hi. I have a piece of code that runs in a Tomcat server and polls a
> remote IMAP server over SSL about once every 15th seconds. The job is
> scheduled using Quartz, and I have configured Quartz to not start a
> new job until the previous one has finished. I.e., it's not a
> multi-threaded environment. For the most part, this works very nicely,
> but about once every 8-12 hours, it hangs trying to connect to the
> IMAP server (my conclusion from looking at the JVM stacktrace). When
> this happens, there's NO evidence whatsoever of a TCP connection
> between the client and the server judging from running netstat on the
> machine where the IMAP server runs! Both the client (JavaMail in
> Tomcat) and the IMAP server (Cyrus 2.2.13-24.2) are running on pretty
> snappy OpenSUSE Linux AMD machines (2 dual cores) with lots of RAM
> and disk. Please note that the very same IMAP server handles all the
> mailboxes for the company (all via SSL), and we've had no problems
> with it. Also note that the timeout that is set to 180000 milliseconds
> doesn't seem to help here. When the problem occurs, this will block
> forever.
>
> Here's the code snippet:
>
>       // This line was added after googling for JavaMail and SSL
>       Security.addProvider(new com.sun.net.ssl.internal.ssl.Provider());
>       Properties props = System.getProperties();
>       props.setProperty("mail.imap.socketFactory.class",
>                         "javax.net.ssl.SSLSocketFactory");
>       props.setProperty("mail.imap.socketFactory.fallback", "false");
>       props.setProperty("mail.imap.starttls.enable", "true");
>       props.setProperty("mail.imap.port", IMAPS_PORT);
>       props.setProperty("mail.imap.socketFactory.port", IMAPS_PORT);
>       props.setProperty("mail.imap.sasl.enable", "true");
>       props.setProperty("mail.imap.timeout", "180000");
>       props.setProperty("mail.imap.connectiontimeout", "180000");
>       Session session = Session.getInstance(props);
>       // session.setDebug(debug);
>       store = session.getStore("imaps");
>       store.connect(mailServer, mailUser, password);
>
> The code blocks in the call to store.connect(). A JVM stack trace
> follows below. Any help to fix or circumvent this problem is highly
> appreciated. Thanks,
>
> Henrik
>
> "scheduler_Worker-3" prio=10 tid=0x00002aabf0101000 nid=0x772e runnable [0x000000004163d000..0x000000004163ec80]
>    java.lang.Thread.State: RUNNABLE
>         at java.net.SocketInputStream.socketRead0(Native Method)
>         at java.net.SocketInputStream.read(SocketInputStream.java:129)
>         at com.sun.net.ssl.internal.ssl.InputRecord.readFully(InputRecord.java:293)
>         at com.sun.net.ssl.internal.ssl.InputRecord.read(InputRecord.java:331)
>         at com.sun.net.ssl.internal.ssl.SSLSocketImpl.readRecord(SSLSocketImpl.java:789)
>         - locked <0x00002aab0db69840> (a java.lang.Object)
>         at com.sun.net.ssl.internal.ssl.SSLSocketImpl.performInitialHandshake(SSLSocketImpl.java:1096)
>         - locked <0x00002aab0db697e8> (a java.lang.Object)
>         at com.sun.net.ssl.internal.ssl.SSLSocketImpl.readDataRecord(SSLSocketImpl.java:744)
>         at com.sun.net.ssl.internal.ssl.AppInputStream.read(AppInputStream.java:75)
>         - locked <0x00002aab0db6a630> (a com.sun.net.ssl.internal.ssl.AppInputStream)
>         at com.sun.mail.util.TraceInputStream.read(TraceInputStream.java:110)
>         at java.io.BufferedInputStream.fill(BufferedInputStream.java:218)
>         at java.io.BufferedInputStream.read(BufferedInputStream.java:237)
>         - locked <0x00002aab0db6a8e0> (a java.io.BufferedInputStream)
>         at com.sun.mail.iap.ResponseInputStream.readResponse(ResponseInputStream.java:97)
>         at com.sun.mail.iap.Response.<init>(Response.java:96)
>         at com.sun.mail.imap.protocol.IMAPResponse.<init>(IMAPResponse.java:61)
>         at com.sun.mail.imap.protocol.IMAPResponse.readResponse(IMAPResponse.java:135)
>         at com.sun.mail.imap.protocol.IMAPProtocol.readResponse(IMAPProtocol.java:261)
>         at com.sun.mail.iap.Protocol.<init>(Protocol.java:114)
>         at com.sun.mail.imap.protocol.IMAPProtocol.<init>(IMAPProtocol.java:104)
>         at com.sun.mail.imap.IMAPStore.protocolConnect(IMAPStore.java:538)
>         - locked <0x00002aab0db6b1c8> (a com.sun.mail.imap.IMAPSSLStore)
>         at javax.mail.Service.connect(Service.java:288)
>         - locked <0x00002aab0db6b1c8> (a com.sun.mail.imap.IMAPSSLStore)
>         at javax.mail.Service.connect(Service.java:169)
>         at com.pws.imagebot.ImageAttachmentExtractor.retrieveMessage(ImageAttachmentExtractor.java:169)
>         at com.pws.scheduling.EmailImageExtractorJob.executeInternal(EmailImageExtractorJob.java:146)
>         at org.springframework.scheduling.quartz.QuartzJobBean.execute(QuartzJobBean.java:86)
>         at org.quartz.core.JobRunShell.run(JobRunShell.java:203)
>         at org.quartz.simpl.SimpleThreadPool$WorkerThread.run(SimpleThreadPool.java:520)
>
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