After Auto-Refresh, Cluster Node Graphs Become Blank

[bkelly1984]

Running Ganglia 3.7.2 on CentOS 8, we discovered that the node graphs in the cluster view section of a ganglia cluster report would go blank after an auto-refresh. On load, the graphs would normally show a CPU or network report like this:

then after an auto-refresh, all graphs would be empty, although high load nodes would still have a colored frame, like this:

Initial investigations suggested that graphs fetched after the update were missing a value for the "g" parameter, which specifies the metric to graph. A lot more troubleshooting found that the cluster_refresh.tpl template was not getting the metric_name variable properly set.

I modified cluster_view.php and moved what is currently line 636, $tpl_data->assign("metric_name", "{$user['metricname']}");, up to above line 608, if (! $refresh) {, so the variable would be set for both refresh and non-refresh cases. This seems to fix the issue.

I am not offering a means to recreate this issue, so I encourage others to speak up if they have a similar problem.

With that, I leave this issue to the Ganglia Gurus to handle as they see fit.

[soon1713]

I've the same issue, running on CentOS 7.9, after upgrade to 3.7.5, all the graph shows "Empty RRDtool command, Likely bad graph config", previously it was fine (older version)

[pkerney]

I have the same problem on Centos 7.9.2009 ganglia 3.7.2 right now.
Workaround by @bkelly1984 seems to work.

[Micket]

Can also confirm this still happens with 3.7.6 from EPEL 9