Feature Request: Logging Quick Retries in Last Layer (MID Layer)

[mirakae]

Problem: Currently, quick retries in the last layer (MID layer) are not logged when last.parent_retry has parent.config set to "simply_retry," and last.simple_server_retry_responses has parent.config set to "500,501,502,504,412."

Request: Enable logging for these quick retries in the described scenario, potential benefits, such as better troubleshooting or monitoring

[ezelkow1]

Have you tried enabling all parent logging with debug enabled to see if you can get what you want?

[mirakae]

Information for the retry is there, but not able to get it into logs:

http_trans_debug_retry_mid.txt

but not able to log it.

[github-actions]

This issue has been automatically marked as stale because it has not had recent activity. Marking it stale to flag it for further consideration by the community.

[bryancall]

Thanks for the request. The capability to log simple/quick parent retries already exists as the ssrc log field (server_simple_retry_count), with surc (server_unavailable_retry_count) as its companion for unavailable-server retries. You can add %<ssrc> and %<surc> to a custom format in logging.yaml.

ssrc reports the per-transaction simple server retry count. It is backed by t_state.current.simple_retry_attempts, which is incremented on every simple parent retry in HttpTransact (PARENT_RETRY with retry type SIMPLE), with no special-casing that would exclude the last (MID) parent layer. So simple retries triggered by parent_retry simply_retry with your simple_server_retry_responses set should be reflected in ssrc.

These fields are documented here:

trafficserver/doc/admin-guide/logging/formatting.en.rst

Lines 218 to 219 in a2c55e3

	surc Proxy Parent unavailable retry count within the current transaction by |TS|.
	ssrc Proxy Parent simple server retry count within the current transaction by |TS|.

They were added in #9694 and first shipped in 10.0.0.

Since the requested logging is available and there has been no further activity, I am closing this. If ssrc does not capture the MID-layer retries in your specific configuration, please reopen with the version you are running, your parent.config and logging.yaml, and a sample log line so we can dig into the exact case.