Environment

• Yugabyte versions 2.12.7, 2.12.8, and 2.12.9.0.
• ysql use cases

Issue

The following postgres database connection attempts will fail:

• Postgres crashes when attempting to connect from database clients such as pg_admin, DBeaver.
• When using ysqlsh the failures are associated with specific queries against pg_catalog such as:

yugabyte=# select * from pg_catalog.pg settings;

Cause

The cause is related to an issue introduced in GH12775 affecting Yugabyte versions 2.12.7, 2.12.8, and 2.12.9.0.

Resolution

Upgrade to a version of Yugabyte 2.12.9.1 or greater, as soon as possible.

Reproduction 

On a tserver attempt to run one of the following queries:

yugabyte=# select * from pg_catalog.pg settings;

or

yugabyte=# show yb_transaction_priority;

The resulting failure will look similar to the following:

yugabyte=# show yb_transaction_priority;
server closed the connection unexpectedly
    This probably means the server terminated abnormally
    before or while processing the request.
    The connection to the server was lost. Attempting reset: Failed.
!> \q

In the postgres.log file, for the associated tserver, the messages similar to following can be observed:

LOG: server process (PID 1801) was terminated by signal 11: Segmentation fault
DETAIL: Failed process was running: select * from pg_catalog.pg_settings;
LOG: terminating any other active server processes
FATAL: the database system is in recovery mode
LOG: all server processes terminated; reinitializing

A corresponding core dump file will be present in the cores directory (default location is /mnt/d0/cores) with corresponding times and PID of the failed process.

-rw-------. 1 yugabyte yugabyte 275275776  core_postgres.1801

Symptoms

External client connections from applications such as pg_admin and DBeaver can also exhibit connection failures due to this issue.  

• An example connection failure from DBeaver can look similar to the following:

• And a connection failure from pg_admin can look similar to the following:

Additional Information

GHI 12775 - Cause of the issue.

GHI13348 - Fix in 2.12.9.1.