[Freeipa-devel] [freeipa PR#2891][opened] ipa-extdom-exop: add instance counter and limit

[sumit-bose]

   URL: https://github.com/freeipa/freeipa/pull/2891
Author: sumit-bose
 Title: #2891: ipa-extdom-exop: add instance counter and limit
Action: opened

PR body:
"""
The user and group lookups done by the extdom plugin might need some
time depending on the state of the service (typically SSSD) handling the
requests.

To avoid that all worker threads are busy waiting on a connect or a
reply from SSSD and no other request can be handled this patch adds an
instance counter and an instance limit for the extdom plugin.

By default the limit will be around 80% of the number of worker threads.
It can be tuned further with the plugin option ipaExtdomMaxInstances
which must in set in ipaextdommaxinstances and should have an integer
value larger than 0 and lesser than the number of worker threads.

If the instance limit is reached the extdom plugin will return LDAP_BUSY
for every new request until the number of instance is again below the
limit.
"""

To pull the PR as Git branch:
git remote add ghfreeipa https://github.com/freeipa/freeipa
git fetch ghfreeipa pull/2891/head:pr2891
git checkout pr2891