Re: Postgres intermittent connection errors: psql.bin: could not connect to server: Cannot assign requested address

["David G. Johnston" <david.g.johnston@xxxxxxxxx>]

On Monday, May 15, 2017, Vamsi Patchipulusu <vpatchipulusu@xxxxxxxxxxx> wrote:

          Error: psql.bin: could not connect to server: Cannot assign requested address

        Is the server running on host "abchost.corp.xyz.com" (xxx.xxx.xxx.xxx) and accepting

        TCP/IP connections on port 5432?

Jmeter is the tool we are using for orchestrating the tests. It  executes a shell script on 50 concurrent  threads.

The  shell script does the following:

a)      Connects to postgres database server using psql.

b)      Issues a single select statement on table with 200 rows .

c)       Writes the results to a text file.

Jmeter client and database host are sitting in the same data center. 

Database OS: RedHat 6.x,

DB Version:  Postgres 9.6

Database is of decent config. 16 CPU, 64GB RAM, SAN storage. 

As you noted this is a client-side error so server specs are immaterial unless the client and server are the same machine.

While some calls are failing with the error:   psql.bin: could not connect to server: Cannot assign requested address

Other calls are successful around the same timeframe may be one to two seconds later..

This points to an O/S problem, possibly configuration.  Or it might just be a problem with JMeter.  In any case failing to bind to an address sporadically isn't really something psql can be blamed for.

Googling jmeter for this turns up a variety of programs and scripts that seem to have this problem when run within JMeter.  Exploring those results may prove fruitful.

David J.