nscd: Improve nscd.conf comments.

This change adds a warning to nscd.conf about running multiple caching
services together and that it may lead to unexpected behaviours. Also we
add a note that enabling the 'shared' option will cause cache hit rates
to be misreported (a side effect of the implementation).

v2
- Rewrite comment to avoid implementation details.

diff --git a/ChangeLog b/ChangeLog
index 393be108513e91ec5b0ff64024469c73567d3643..96d1b9c744156a32a207a6227816bb1bcf07e993 100644 (file)
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,7 @@
+2019-08-19  Carlos O'Donell  <carlos@redhat.com>
+
+       * nscd/nscd.conf: Add warning and comment about shared option.
+
 2019-08-19  Carlos O'Donell  <carlos@redhat.com>
 
        * nss/nsswitch.conf: Expand comments, and simplify defaults.

diff --git a/nscd/nscd.conf b/nscd/nscd.conf
index 39b875912dbaf730588e59a3dfd34a014057c83d..487ffe461d7c6ceea91792cfb3b4922eb006ed8e 100644 (file)
--- a/nscd/nscd.conf
+++ b/nscd/nscd.conf
@@ -3,6 +3,9 @@
 #
 # An example Name Service Cache config file.  This file is needed by nscd.
 #
+# WARNING: Running nscd with a secondary caching service like sssd may lead to
+#          unexpected behaviour, especially with how long entries are cached.
+#
 # Legal entries are:
 #
 #      logfile                 <file>
@@ -23,6 +26,9 @@
 #      check-files             <service> <yes|no>
 #      persistent              <service> <yes|no>
 #      shared                  <service> <yes|no>
+#      NOTE: Setting 'shared' to a value of 'yes' will accelerate the lookup,
+#            but those lookups will not be counted as cache hits
+#            i.e. 'nscd -g' may show '0%'.
 #      max-db-size             <service> <number bytes>
 #      auto-propagate          <service> <yes|no>
 #