CopyManager.copyOut stuck in socket read

Hi Team,

We are using a java application that does something like "COPY (select xyz from abc ) TO filename.csv.gz" using JDBC to postgres 9.3.11 server.

Java version: openjdk version "1.8.0_151"
Postgres server: PostgreSQL 9.3.11 on x86_64-unknown-linux-gnu, compiled by gcc (GCC) 4.8.5 20150623 (Red Hat 4.8.5-4), 64-bit
JDBC driver: postgresql-8.4-701.jdbc3.jar

* The problem is that the COPY is just running there forever even though the table it is referring to has <10 columns with ~50 rows.

* Thread dump indicates copyOut is stuck in socket read. There is no enforcement of a timeout in application nor we have added a statement_timeout.

* We want to understand why it is stuck as it has been running for more than 3 days now. Inspecting the target csv.gz file, it has no content in it yet.

* The CPU utilization of the pid representing the query ( captured from pg_stat_activity ) shows close to 100%. Is this some known issue?

* I know we are in old version but would like to know if this is a bug that's already seen? Looking at release notes, I'm not able to find out.

"OurThread" #21 prio=5 os_prio=0 tid=0x00007f37fc3ed570 nid=0x23ca7 runnable [0x00007f37e5d79000]
java.lang.Thread.State: RUNNABLE
at java.net.SocketInputStream.socketRead0(Native Method)
at java.net.SocketInputStream.socketRead(SocketInputStream.java:116)
at java.net.SocketInputStream.read(SocketInputStream.java:171)
at java.net.SocketInputStream.read(SocketInputStream.java:141)
at org.postgresql.core.VisibleBufferedInputStream.readMore(VisibleBufferedInputStream.java:135)
at org.postgresql.core.VisibleBufferedInputStream.ensureBytes(VisibleBufferedInputStream.java:104)
at org.postgresql.core.VisibleBufferedInputStream.read(VisibleBufferedInputStream.java:73)
at org.postgresql.core.PGStream.ReceiveChar(PGStream.java:259)
at org.postgresql.core.v3.QueryExecutorImpl.processCopyResults(QueryExecutorImpl.java:893)
at org.postgresql.core.v3.QueryExecutorImpl.startCopy(QueryExecutorImpl.java:713)
- locked <0x00000000fb497b68> (a org.postgresql.core.v3.QueryExecutorImpl)
at org.postgresql.copy.CopyManager.copyOut(CopyManager.java:63)
at org.postgresql.copy.CopyManager.copyOut(CopyManager.java:103)
at etl.task.extract.SelectFromDatabaseTableTask.execute(SelectFromDatabaseTableTask.java:118)
at etl.jobprocessor.JobApplication.mainline(JobApplication.java:250)
at etl.application.Application.run(Application.java:258)
at java.lang.Thread.run(Thread.java:748)

Thanks,
Karthik S

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