Red Hat Bugzilla – Bug 594668
ypbind probes for the fastest server too often
Last modified: 2013-09-23 07:13:31 EDT
Description of problem:
The ypbind manual page says that it checks the current server every 20s to confirm it is up, and also pings all configured servers every 15 minutes to check on which is currently the fastest to respond. In fact it pings the servers every minute which may cause ypbind to flip the servers very often.
Version-Release number of selected component (if applicable):
Steps to Reproduce:
1. configure ypbind to try to contact more servers, i.e. add two servers to /etc/yp.conf (one of them must be reachable):
2. start ypbind in the debug mode
3. it logs out the pings of the servers
The "Check new for fastest server." logs appear every minute:
The "Check new for fastest server" logs appear every 15 minutes (as documented)
This seems to be caused by the ypbind-mt-1.19-log-binds.patch which contains the following chunk:
@@ -1031,7 +1067,8 @@ test_bindings (void *param __attribute__
lastcheck += ping_interval;
- if (lastcheck >= 900) /* 900 = 15min. */
+ //if (lastcheck >= 900) /* 900 = 15min. */
+ if (lastcheck >= 60) /* 900 = 15min. */
At the first glance it looks like this has been added for the debugging purposes to test the patch for the bug #198689. We should revert this part or explain why does the interval have to be shortened this much and fix the documentation.
Correct, it seems it was added for debugging purposes.
The limit should be set back to 900.
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Technical note added. If any revisions are required, please edit the "Technical Notes" field
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Each NIS client can bind to different NIS servers, but can only be bound to one server at a time. To maintain its connection to a server, an NIS client checks connection to an active server every 20 seconds and once in a while tries to find the fastest available server. Previously, clients searched for the fastest server every minute, which sometimes caused heavy traffic and response delays. With this update, clients search for the fastest server every 15 minutes, preventing this bug.
just a note, with RHEL5.8-SERVER-20111030.0 BETA 1.0 - ypbind-1.19-12.el5_6.1 this fails our regression testing, it seems that ypbind doesn't do the checks at all (IOW, the debug log does not contain any single occurence of "Checking for new fastest server.")
(In reply to comment #20)
> just a note, with RHEL5.8-SERVER-20111030.0 BETA 1.0 - ypbind-1.19-12.el5_6.1
> this fails our regression testing, it seems that ypbind doesn't do the checks
> at all (IOW, the debug log does not contain any single occurence of "Checking
> for new fastest server.")
seems like misconfiguration which wasn't discovered before thanks to different lab environment
[kvolny@kvolny bz594668-ypbind-probes-for-the-fastest-server-too-often]$ cvs diff -r 1.9 runtest.sh
RCS file: /cvs/dist/tests/ypbind/Regression/bz594668-ypbind-probes-for-the-fastest-server-too-often/runtest.sh,v
retrieving revision 1.9
retrieving revision 1.10
diff -r1.9 -r1.10
> rlFileBackup /etc/yp.conf
> echo 'domain AZOR server 18.104.22.168' >> /etc/yp.conf