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5.5.3. Visualizing the action sequence

Another handy feature is the ability to generate a visual graph of the actions needed, using the --dot-file option. This relies on the separate Graphviz [6] project.

Example 5.10. Generate a visual graph of cluster actions from a saved CIB

crm_simulate --simulate --xml-file $FILENAME --dot-file $
dot $ -Tsvg > $FILENAME.svg
$ will contain a GraphViz representation of the cluster’s response to your changes, including all actions with their ordering dependencies.
$FILENAME.svg will be the same information in a standard graphical format that you can view in your browser or other app of choice. You could, of course, use other dot options to generate other formats.
How to interpret the graphical output:

Example 5.11. Small Cluster Transition

An example transition graph as represented by Graphviz
In the above example, it appears that a new node, pcmk-2, has come online and that the cluster is checking to make sure rsc1, rsc2 and rsc3 are not already running there (indicated by the rscN_monitor_0 entries). Once it did that, and assuming the resources were not active there, it would have liked to stop rsc1 and rsc2 on pcmk-1 and move them to pcmk-2. However, there appears to be some problem and the cluster cannot or is not permitted to perform the stop actions which implies it also cannot perform the start actions. For some reason, the cluster does not want to start rsc3 anywhere.

Example 5.12. Complex Cluster Transition

Complex transition graph that you're not expected to be able to read

[6] Graph visualization software. See for details.