Bug ID 912517: Database monitor marks pool member down if 'send' is configured but no 'receive' strings are configured

Last Modified: Sep 29, 2022

Bug Tracker

Affected Product:  See more info
BIG-IP DNS, GTM, LTM(all modules)

Known Affected Versions:, 17.0.0, 16.1.3, 16.1.2, 16.1.1, 16.1.0, 15.1.7, 15.1.6, 15.1.5, 15.1.4, 15.1.3, 15.1.2, 15.1.1, 15.1.0,,,,,, 14.1.4, 14.1.3, 14.1.2, 14.1.0,, 13.1.4, 13.1.3, 13.1.1, 13.1.0, 12.1.6, 12.1.5, 12.1.4, 12.1.3, 12.1.2

Fixed In:
17.0.0,,,, 13.1.5

Opened: May 28, 2020
Severity: 3-Major


If an LTM database monitor type (MySQL, MSSQL, Oracle, or PostgreSQL database monitor type) is configured with a 'send' string but with no 'receive' string to issue a user-specified database query, pool members using this monitor are marked DOWN, even though a connection to the configured database completed successfully.


The database monitor marks the pool member down, even in cases where the pool member is actually pingable.


-- An LTM pool or pool members is configured to use an LTM database (MySQL, MSSQL, Oracle or PostgreSQL) monitor type. -- A 'send' string is configured for the monitor. -- A 'receive' string is not configured.


To work around this issue, configure 'send' and 'recv' strings for the database monitor that will always succeed when successfully connected to the specified database (with the configured username and password, if applicable).

Fix Information

For BIG-IP versions 17.0.0 and earlier, a database monitor no longer marks pool member down if 'send' is configured but no 'receive' strings are configured.

Behavior Change