Postgres SSL SYSCALL error: EOF detected with python and psycopg

Question

Using psycopg2 package with python 2.7 I keep getting the titled error: psycopg2.DatabaseError: SSL SYSCALL error: EOF detected

It only occurs when I add a WHERE column LIKE ''%X%'' clause to my pgrouting query. An example:

SELECT id1 as node, cost FROM PGR_Driving_Distance(
  'SELECT id, source, target, cost 
     FROM edge_table
     WHERE cost IS NOT NULL and column LIKE ''%x%'' ',
  1, 10, false, false)

Threads on the internet suggest it is an issue with SSL intuitively, but whenever I comment out the pattern matching side of things the query and connection to the database works fine.

This is on a local database running Xubuntu 13.10.

After further investigation: It looks like this may be cause by the pgrouting extension crashing the database because it is a bad query and their are not links which have this pattern.

Will post an answer soon ...

Answer 1

I ran into this problem when running a slow query in a Droplet on a Digital Ocean instance. All other SQL would run fine and it worked on my laptop. After scaling up to a 1 GB RAM instance instead of 512 MB it works fine so it seems that this error could occur if the process is running out of memory.

Answer 2

This issue occurred for me when I had some rogue queries running causing tables to be locked indefinitely. I was able to see the queries by running:

SELECT * from STV_RECENTS where status='Running' order by starttime desc;

then kill them with:

SELECT pg_terminate_backend(<pid>);

Answer 3

You may need to express % as %% because % is the placeholder marker. http://initd.org/psycopg/docs/usage.html#passing-parameters-to-sql-queries

Answer 4

Very similar answer to what @FoxMulder900 did, except I could not get his first select to work. This works, though:

WITH long_running AS (
    SELECT pid, now() - pg_stat_activity.query_start AS duration, query, state
    FROM pg_stat_activity
    WHERE (now() - pg_stat_activity.query_start) > interval '1 minutes'
      and state = 'active'
)
SELECT * from long_running;

If you want to kill the processes from long_running just comment out the last line and insert SELECT pg_cancel_backend(long_running.pid) from long_running ;

Answer 5

I got this error running a large UPDATE statement on a 3 million row table. In my case it turned out the disk was full. Once I had added more space the UPDATE worked fine.

Answer 6

In my case that was OOM killer (query is too heavy)

Check dmesg:

dmesg | grep -A2 Kill

In my case:

Out of memory: Kill process 28715 (postgres) score 150 or sacrifice child