# 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.
1. Set `LogLevel` to `trace8`
1. 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.
1. 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"
1. If using `mod_disk_cache`, specify a temporary `CacheRoot` in httpd.conf for the recreate
1. Start IHS
1. Recreate the problem
1. 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.
1. Set `LogLevel` to `debug`
1. 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.
1. 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"
1. If using `mod_disk_cache`, specify a temporary `CacheRoot` in httpd.conf for the recreate
1. Start IHS
1. Recreate the problem
1. 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. 


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