Symptom
STP pushing topology change notification causing CPU load and memory depletion.
Conditions
Condition1 : Catalyst9000 platforms
Condition2 : Version from 17.3.1 to 17.3.4
Condition3 : chunk error for stp is seen
%SYS-4-CHUNKSIBLINGSEXCEED: Number of siblings in a chunk has gone above the threshold. Threshold:10000 Sibling-Count:10001 Chunk:0x80007FBDC4AD4F40 Name:Crimson Stp sta -Process= "Spanning Tree", ipl= 2, pid= 242
%SYS-2-CHUNKEXPANDFAIL: Could not expand chunk pool for Crimson Stp sta.
%SYS-4-FREEMEMLOW: Top Allocator Name: Crimson Stp
Workaround
Avoid constant STP togology changes
Further Problem Description
Continuous tracebacks could be observed.
*Mar 10 08:19:31.994: %PLATFORM_MATM-4-QUEUE_OVERLIMIT: MATM dropped learn cache batch messages as queue limit has reached.
*Mar 10 08:19:32.168: %SYS-4-CHUNKSIBLINGSEXCEED: Number of siblings in a chunk has gone above the threshold. Threshold:10000 Sibling-Count:29037 Chunk:0x80007F2432928A50 Name:Crimson Stp sta -Process= "Chunk Manager", ipl= 2, pid= 1
-Traceback= 1#c79fa717ffad0d3f09336e0519d3b8c4 :55BCC5340000+AE8A83B
