6.18. Process dumps

When a process on the Steelhead fails, the operating system will generate a core dump of it: A copy of all the memory of the process as it was in use at the moment it failed. The size of the core dump depends on the size of the process, for a core dump of the optimization service this can be hundreds of megabytes.

After the core dump is generated, the process pm will tell the process mgmtd to generate a system dump and merge the two dumps into a process dump. This process might take a while, during which the process does not get restarted.

It can be necessary in the lifetime of a case that Riverbed TAC requires a process dump of the optimization service. The way to generate one is to use the command debug service clone dump start or the command pm process <PROCESS> send-signal SIGQUIT.

The command debug service clone dump start will create a clone of the optimization service first and generates a process dump of the clone. This will cause the optimization and the normal traffic to continue.

Figure 6.96. Generating a process dump of the process sport by cloning it

SH # debug service clone dump start
[... some times passes ...]
SH # show files process-dump
SH-sport-20130102-123456.tar.gz
SH # file process-dump SH-sport-20130102-123456.tar.gz ftp://192.168.1.1/incoming/SH-sport \
    -20130102-123456.tar.gz
SH # show info
Current User:      admin

Status:            Healthy
Config:            working
Appliance Up Time: 12d 11h 20m 7s
Service Up Time:   12d 11h 18m 14s
Managed by CMC:    yes
Temperature (C):   44

The command pm process <PROCESS> send-signal SIGQUIT will terminate the optimization service and then generate a process dump of it. This will cause the optimized TCP sessions to be aborted and the optimization service to be restarted.

Figure 6.97. Generating a process dump of the process sport by restarting it

SH # pm process sport send-signal SIGQUIT
[... some times passes ...]
SH # show files process-dump
SH-sport-20130102-123456.tar.gz
SH # file process-dump SH-sport-20130102-123456.tar.gz ftp://192.168.1.1/incoming/SH-sport \
    -20130102-123456.tar.gz
SH # show info
Current User:      admin

Status:            Healthy
Config:            working
Appliance Up Time: 12d 11h 24m 23s
Service Up Time:   1m 31s
Managed by CMC:    yes
Temperature (C):   44