IHS Caching Mustgather

Background

IBM HTTP Server includes caching components that can save responses to memory or disk based on standard HTTP caching mechanisms.

Collecting data manually

9.0 and later

  1. Stop IHS.

  2. Set LogLevel to trace8

  3. Uncomment the mod_net_trace example in httpd.conf (or httpd.conf.default if the sample is not present). Ensure the NetTraceFile path is valid and has ample free space.

  4. Append the following directive to httpd.conf

    GlobalLog logs/cache-debug.log "%h %l %u %t "%r" %>s %b %D %{RH}e %{WAS}e Age=%{Age}o CCI%{Cache-Control}i %{Last-Modified}o ETAGO=%{Etag}o IM=%{If-Match}i INM=%{If-None-Match}i IMS=%{If-Modified-Since}i CCO=%{Cache-Control}o EXP=%{Expires}o V=%{Vary}o CH=%{cache-hit}e CR=%{cache-revalidate}e CI=%{cache-invalidate}e CS=%{cache-status}e"

  5. If using mod_disk_cache, specify a temporary CacheRoot in httpd.conf for the recreate

  6. Start IHS

  7. Recreate the problem

  8. Collect the nettrace, error, access, cache-debug.log, IHS configuration files, and a zip of the CacheRoot if applicable. If it is not feasible to send the entire CacheRoot, find the relevant entries with grep -a on the files in the root.

8.5.5 and earlier

  1. Stop IHS.

  2. Set LogLevel to debug

  3. Uncomment the mod_net_trace example in httpd.conf (or httpd.conf.default if the sample is not present). Ensure the NetTraceFile path is valid and has ample free space.

  4. Append the following directive to httpd.conf, once globally and once per virtual host with a unique filename as the first parameter:

    CustomLog logs/cache-debug.log "%h %l %u %t "%r" %>s %b %D %{RH}e %{WAS}e Age=%{Age}o CCI%{Cache-Control}i %{Last-Modified}o ETAGO=%{Etag}o IM=%{If-Match}i INM=%{If-None-Match}i IMS=%{If-Modified-Since}i CCO=%{Cache-Control}o EXP=%{Expires}o V=%{Vary}o CH=%{cache-hit}e CR=%{cache-revalidate}e CI=%{cache-invalidate}e CS=%{cache-status}e"

  5. If using mod_disk_cache, specify a temporary CacheRoot in httpd.conf for the recreate

  6. Start IHS

  7. Recreate the problem

  8. Collect the nettrace, error, access, cache-debug.log(s), IHS configuration files, and a zip of the CacheRoot if applicable. If it is not feasible to send the entire CacheRoot, find the relevant entries with grep -a on the files in the root.