Unusual Postgres 9.4 error message

So, I was looking in the Postgres log file for today on our DB server, and it's nothing but lines like these:

< 2017-06-12 18:37:59.249 UTC >STATEMENT: SELECT "main_instance"."id", "main_instance"."uuid", "main_instance"."hostname", "main_instance"."created", "main_instance"."modified", "main_instance"."version", "main_instance"."capacity" FROM "main_instance" LIMIT 1 FOR UPDATE NOWAIT
< 2017-06-12 18:38:05.289 UTC >ERROR: could not obtain lock on row in relation "main_instance"
< 2017-06-12 18:38:05.289 UTC >STATEMENT: SELECT "main_instance"."id", "main_instance"."uuid", "main_instance"."hostname", "main_instance"."created", "main_instance"."modified", "main_instance"."version", "main_instance"."capacity" FROM "main_instance" LIMIT 1 FOR UPDATE NOWAIT
< 2017-06-12 18:38:12.496 UTC >ERROR: could not obtain lock on row in relation "main_instance"
< 2017-06-12 18:38:12.496 UTC >STATEMENT: SELECT "main_instance"."id", "main_instance"."uuid", "main_instance"."hostname", "main_instance"."created", "main_instance"."modified", "main_instance"."version", "main_instance"."capacity" FROM "main_instance" LIMIT 1 FOR UPDATE NOWAIT
< 2017-06-12 18:38:59.267 UTC >ERROR: could not obtain lock on row in relation "main_instance"
< 2017-06-12 18:38:59.267 UTC >STATEMENT: SELECT "main_instance"."id", "main_instance"."uuid", "main_instance"."hostname", "main_instance"."created", "main_instance"."modified", "main_instance"."version", "main_instance"."capacity" FROM "main_instance" LIMIT 1 FOR UPDATE NOWAIT

Our setup is a little different, as we are running the 2ndQuadrant BDR-enabled Postgres 9.4 package on the server:

[14:39:01 root(at)dch282ml5pgsql> yum list installed |grep postgres
Repository epel is listed more than once in the configuration
Repository epel-source is listed more than once in the configuration
Repository jlaska-rabbitmq is listed more than once in the configuration
Repository pgdg94 is listed more than once in the configuration
Repository pgdg94 is listed more than once in the configuration
Repository pgdg94-source is listed more than once in the configuration
postgresql-bdr94-2ndquadrant-redhat.noarch

and the OS is RHEL 7.3.

As far as I can tell, the DB is up, accepting connections, and basically working the way it should. So those error messages are confusing me. Are they something that can be ignored? If so, is it possible to turn them off?

Just trying to figure out what is trying to access the database that could be generating statements like that.

Any information you could provide would be greatly appreciated.

Thanks.

Brad Keefer
Red Hat Consultant - RHCSA

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