Spring Integration Mail Inbound Channel Adapter configured for POP3 access and using a poller configuration hangs after running for some time

0
votes
<int:channel id="emailInputChannel"/>
<!-- Email Poller. Only one poller thread -->   
<task:executor id="emailPollingExecutor" pool-size="1" /> 
<int-mail:inbound-channel-adapter id="pop3EmailAdapter" store-uri="pop3://${pop3.user}:${pop3.pwd}@${pop3.server.host}/Inbox" 
channel="emailInputChannel" should-delete-messages="true" auto-startup="true" java-mail-properties="javaMailProperties">
           <int:poller max-messages-per-poll="1" fixed-delay="${email.poller.delay}" task-executor="emailPollingExecutor"/>
</int-mail:inbound-channel-adapter>
<!-- Java Mail POP3 properties -->
<util:properties id="javaMailProperties">
  <beans:prop key="mail.debug">true</beans:prop> 
  <beans:prop key="mail.pop3.port">${pop3.server.port}</beans:prop> 
</util:properties>

This application polls for emails containing application file attachments which contain the data to process. The email attachments are sent typically a few a day and are relatively sporadic. Since the files contain data for bulk load, we resorted to this configuration with a single poller for the Inbound POP3 mail adapter. Having multiple pollers caused duplicate poller invocations to pull the same email while another poller is processing it. With this configuration, however, the single poller hangs after some time with no indications of the problem in the logs. Please review what is wrong with this configuration. Also, is there is an alternative way to trigger the email adapter (e.g cron etc at a periodic interval)? I am using Spring Integration 2.1

1
spring-integration

1 Answers

0
votes

A hung poller is most likely caused by the the thread stuck in user code. I see you have mail.debug=true. If that shows no activity then a hung thread is probably the cause. Use us jstack to take a thread dump.

Yes, you can use a crown expression but that's unlikely to change things.

2.1 is extremely old but I still think a hung thread is the cause.