Why is the Ganglia overview page for my Amazon EMR cluster blank?

Last updated: 2022-05-27

When I open the Ganglia UI, I don't see the default overview for my Amazon EMR cluster. All I see is a blank page.


This is a known issue that affects Amazon EMR release versions 5.30.0 and 6.0.0. This issue is resolved in Amazon EMR release version 5.30.1.

To resolve the issue on Amazon EMR 5.30.0 or 6.0.0, modify cluster_view.php manually, or as an Amazon EMR step.

Modify cluster_view.php manually

1.    Connect to the master node using SSH.

2.    Open the /usr/share/ganglia/cluster_view.php file.

3.    On line 26, change $context_metrics = "" to $context_metrics = array(). For example, here's how the file looks before you modify it:

25 function get_picker_metrics($metrics, $reports, $gweb_root, $graph_engine) {
26   $context_metrics = "";
27   if (count($metrics)) {

Here's how the file looks after you modify it:

25 function get_picker_metrics($metrics, $reports, $gweb_root, $graph_engine) {
26   $context_metrics = array();
27   if (count($metrics)) {

4.    Refresh the Ganglia UI to see the cluster overview page.

Modify cluster_view.php as a step

1.    Copy the following command into a .sh file. You can store the file in an Amazon Simple Storage Service (Amazon S3) bucket.

sudo sed -i '26s/ \$context_metrics \= \"\"\;/ \$context_metrics \= array\(\)\;/g' /usr/share/ganglia/cluster_view.php

2.    Add the .sh file to the cluster as a step. Replace these values in the following example:

j-XXXXXXXX: your cluster identifier
s3://awsdoc-example-bucket/sample.sh: the path to the .sh file that you created in step 1

aws emr add-steps --cluster-id j-XXXXXXXX --steps Type=CUSTOM_JAR,Name="Fix Ganglia",Jar="s3://us-east-1.elasticmapreduce/libs/script-runner/script-runner.jar",ActionOnFailure=CONTINUE,Args=[s3://awsdoc-example-bucket/sample.sh]

Note: If you receive errors when running AWS Command Line Interface (AWS CLI) commands, be sure that you’re using the most recent version of the CLI.

3.    Refresh the Ganglia UI to see the cluster overview page.

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