Bug ID 860517: MCPD may crash on startup with many thousands of monitors on a system with many CPUs.

Last Modified: Sep 13, 2023

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

Known Affected Versions:
12.1.0, 12.1.1, 12.1.2, 12.1.3,,,,,,,, 12.1.4,, 12.1.5,,, 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,,,,,,,,, 14.1.3, 15.0.0, 15.0.1,,,,, 15.1.0,,,,,

Fixed In:
16.0.0, 15.1.1,,,

Opened: Dec 12, 2019

Severity: 2-Critical


MCPD can crash with out of memory when there are many bigd processes (systems with many CPU cores) and many pool members/nodes/monitors. As a guideline, approximately 100,000 pool members, nodes, and monitors can crash a system that has 10 bigd processes (BIG-IP i11800 platforms). tmm crash


The mcpd process crashes. Traffic disrupted while mcpd restarts.


-- Tens of thousands of pool members, nodes, and/or monitors. -- Multiple (generally 6 or more) bigd processes. -- System startup or bigstart restart.


Set the db variable bigd.numprocs to a number smaller than the number of bigd processes currently being started.

Fix Information

The memory efficiency of MCPD has been improved. This allows very large BIG-IP configurations to be used successfully.

Behavior Change

Guides & references

K10134038: F5 Bug Tracker Filter Names and Tips