Bind Exception (I read the others first I promise)

[Rob Stone]

I know there are a million of these posts, but this is a little different. We are using vended code for part of our data processing system, and part of the system sends emails to clients if certain events take place on data insertion or deletion. Recently we have started getting java.net.BindException: Address already in use exceptions. We checked the repository history, and nothing has changed in our code in the last 6 months for this system. We have already tried the typical solutions for this issue including increasing the number of connections allowed to the port with little success. We had a meeting with the vendor, and I asked if anything had changed in their code, and if they would assure that all connections in their code are explicitly closed. They indicated that they are explicitly closing all sockets before and after each use. However they didn't show us the code so there is no way for me to know if this is true. So, the only thing I can think of to do is continue to increase the number of connections to the port until we stop getting bind exceptions. So, what is the industry standard for max number of connections to port 25; is there one? Also if anyone has any other suggestions I would greatly appreciate it? Thanks so much in advance, Robert (p.s. I included as much of the log as the forum would allow)

20210505112127.716 ERROR m.fiserv.ppx.business.notification.EmailNotifier : MessagingException from notify
javax.mail.MessagingException: Could not connect to SMTP host: SERVER.URL.COM, port: 25;
 nested exception is:
java.net.BindException: Address already in use: connect
at com.sun.mail.smtp.SMTPTransport.openServer(SMTPTransport.java:1545)
at com.sun.mail.smtp.SMTPTransport.protocolConnect(SMTPTransport.java:453)
Caused by:
java.net.BindException: Address already in use: connect
at java.net.DualStackPlainSocketImpl.connect0(Native Method)
at java.net.DualStackPlainSocketImpl.socketConnect(DualStackPlainSocketImpl.java:90)
at java.net.AbstractPlainSocketImpl.doConnect(AbstractPlainSocketImpl.java:380)
20210505131529.950 ERROR erv.ppx.web.controller.AuditReportViewController : Error while generating HTML
net.sf.jasperreports.engine.JRException: Error writing to OutputStream writer : CorpAdminAuditReport
at net.sf.jasperreports.engine.export.JRHtmlExporter.exportReport(JRHtmlExporter.java:496)
at com.fiserv.ppx.web.controller.AuditReportViewController.generateReport(AuditReportViewController.java:184)
Caused by:
com.ibm.wsspi.webcontainer.ClosedConnectionException: OutputStream encountered error during write
at com.ibm.ws.webcontainer.channel.WCCByteBufferOutputStream.write(WCCByteBufferOutputStream.java:188)
at com.ibm.ws.webcontainer.srt.SRTOutputStream.write(SRTOutputStream.java:97)
20210505140706.240 ERROR com.fiserv.ppx.business.db.DBConnectionUtil      : Exception in getting for AppServer connection from DataSource.
com.ibm.websphere.ce.cm.ConnectionWaitTimeoutException: J2CA1010E: Connection not available; timed out waiting for 180,005 seconds.
at com.ibm.ws.rsadapter.AdapterUtil.toSQLException(AdapterUtil.java:1680)
at com.ibm.ws.rsadapter.jdbc.WSJdbcDataSource.getConnection(WSJdbcDataSource.java:661)
at com.ibm.ws.rsadapter.jdbc.WSJdbcDataSource.getConnection(WSJdbcDataSource.java:611)
Caused by:
com.ibm.websphere.ce.j2c.ConnectionWaitTimeoutException: J2CA1010E: Connection not available; timed out waiting for 180,005 seconds.
at com.ibm.ejs.j2c.FreePool.createOrWaitForConnection(FreePool.java:1781)
at com.ibm.ejs.j2c.PoolManager.reserve(PoolManager.java:3834)
at com.ibm.ejs.j2c.PoolManager.reserve(PoolManager.java:3082)
20210505140731.341 ERROR com.fiserv.ppx.business.db.DBConnectionUtil      : Exception in getting for AppServer connection from DataSource.
com.ibm.websphere.ce.cm.ConnectionWaitTimeoutException: J2CA1010E: Connection not available; timed out waiting for 180,010 seconds.
at com.ibm.ws.rsadapter.AdapterUtil.toSQLException(AdapterUtil.java:1680)
at com.ibm.ws.rsadapter.jdbc.WSJdbcDataSource.getConnection(WSJdbcDataSource.java:661)
at com.ibm.ws.rsadapter.jdbc.WSJdbcDataSource.getConnection(WSJdbcDataSource.java:611)
Caused by:
com.ibm.websphere.ce.j2c.ConnectionWaitTimeoutException: J2CA1010E: Connection not available; timed out waiting for 180,010 seconds.
at com.ibm.ejs.j2c.FreePool.createOrWaitForConnection(FreePool.java:1781)
at com.ibm.ejs.j2c.PoolManager.reserve(PoolManager.java:3904)
at com.ibm.ejs.j2c.PoolManager.reserve(PoolManager.java:3082)
20210505140731.341 ERROR com.fiserv.ppx.sso.controller.SSOController      : SSO Configuration error
java.lang.NullPointerException
at com.fiserv.ppx.business.db.PPXDbTransactionManager.<init>(PPXDbTransactionManager.java:60)
at com.fiserv.ppx.sso.impl.SSOLoginAuthenticator.authenticateSSOUser(SSOLoginAuthenticator.java:157)

[Matthew Bendford]

I've encountered java.net.BindException: Address already in use: bind quite a lot when trying to open a new ServerSocket on an already bound port - but I never read java.net.BindException: Address already in use: connect.
From what I was able to gather by a quick google search it looks like your process uses up all available limits - like I often get when compiling some big projects running out of open file limits. This in turn means that your code somehow opens A LOT of connections simultaneously and by this hitting the ulimit max.
So, instead of trying to track down some external lib to be an issue first look at how much your own code does.
Also: Hitting the ulimit max is also caused by running too many processes with the same user. So, maybe neither your code nor the lib changed - but has anything else running with the same user on the host? A very quick and easy way to check what's going on is to use htop (a more fancy version of traditional top) and have a look how mandy processes and threads are currently running with the same uid. Also also: Have a look what ulimit -a gives and what your current limits are.
I'm sure the issue here seems overload of the system.
Note: If you're running a VM or some sort of container like docker: Check the overall system resources on the bare metal host machine. Maybe another tip: How about just fully cold restart the host machine to clear out filled up caches?
My bet here on this one is the root cause is somewhat way different than some mail client code not able to push some message to some mail server.