Bug ID 758041: LTM Pool Members may not be updated accurately when multiple identical database monitors are configured.

Last Modified: Sep 13, 2023

Affected Product(s):
BIG-IP LTM(all modules)

Known Affected Versions:
11.5.1, 11.5.2, 11.5.3, 11.5.4, 11.5.5, 11.5.6, 11.5.7, 11.5.8, 11.5.9, 11.5.10, 11.6.0, 11.6.1, 11.6.2, 11.6.3,,,,, 11.6.4, 11.6.5,,,, 12.0.0, 12.0.0 HF1, 12.1.0 HF1, 12.0.0 HF2, 12.1.0 HF2, 12.0.0 HF3, 12.0.0 HF4, 12.1.1 HF1, 12.1.1 HF2, 12.1.2 HF1, 12.1.2 HF2, 12.1.0, 12.1.1, 12.1.2, 12.1.3,,,,,,,, 12.1.4,, 12.1.5,,,, 12.1.6, 13.0.0, 13.0.0 HF1, 13.0.0 HF2, 13.0.0 HF3, 13.0.1, 13.1.0,,,,,,,,, 13.1.1,,,,, 13.1.3,,,,, 14.0.0,,,,,, 14.0.1,, 14.1.0,,,,,, 14.1.2,,,,,,, 15.0.0, 15.0.1,,,,, 15.1.0,,,,,, 15.1.1, 15.1.2,, 15.1.3,, 15.1.4

Fixed In:

Opened: Feb 07, 2019

Severity: 3-Major


When two or more LTM database monitors (MSSQL, MySQL, PostgreSQL, Oracle) with identical 'send' and 'recv' strings are configured and applied to different LTM pools (with at least one pool member in each), the monitor status of some LTM pool members may not be updated accurately. Other parameters of the affected LTM monitors that differ (such as 'recv row' or 'recv column' indicating where the specified 'recv' string should be found in the result set) may cause pool members using one of the affected monitors to connect to the same database to be marked UP, while LTM pool members using another affected monitor may be marked DOWN. As a result of this issue, LTM pool members that should be marked UP or DOWN by the configured LTM monitor may instead be marked according to another affected monitor's configuration, resulting in the affected LTM pool members being intermittently marked with an incorrect state. After the next monitor ping interval, affectedLTM pool members members may be marked with the correct state.


Monitored LTM pool members using an LTM database monitor (MSSQL, MySQL, PostgreSQL, Oracle) randomly go offline/online.


This may occur when multiple LTM database monitors (MSSQL, MySQL, PostgreSQL, Oracle) are configured with identical 'send' and 'recv' parameters, and applied to different LTM pools/members which share the same IP address and Port values. For example: ltm monitor mysql mysql_monitor1 { ... recv none send "select version();" ... } ltm monitor mysql mysql_monitor2 { ... recv none send "select version();" ... }


To avoid this issue, configure each LTM database monitor with values that make the combined parameters unique by changing either the 'send' or the 'recv' parameters, or both. For example: ltm monitor mysql mysql_monitor1 { ... recv none send "select version();" ... } ltm monitor mysql mysql_monitor2 { ... recv 5.7 send "select version();" ... }

Fix Information

The system now correctly updates LTM pool members when multiple identical LTM database monitors are configured.

Behavior Change

Guides & references

K10134038: F5 Bug Tracker Filter Names and Tips