Understanding master.log

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I'm running ros indigo on ubuntu 14.04. I'm having some stability issues regarding nodes being able to subscribe to each other over time. Just trying to do some investigating, I've noticed that some nodes constantly looks for new params and the master log keeps publishing this. Is this normal?

[rosmaster.master][INFO] 2015-10-22 11:04:34,134: +PARAM [/amcl/initial_pose_y] by /amcl
[rosmaster.master][INFO] 2015-10-22 11:04:34,135: +PARAM [/amcl/initial_pose_a] by /amcl
[rosmaster.master][INFO] 2015-10-22 11:04:34,135: +PARAM [/amcl/initial_cov_xx] by /amcl
[rosmaster.master][INFO] 2015-10-22 11:04:34,136: +PARAM [/amcl/initial_cov_yy] by /amcl
[rosmaster.master][INFO] 2015-10-22 11:04:34,137: +PARAM [/amcl/initial_cov_aa] by /amcl

I'm also looking for documents or anything would would show me how to understand the master.log, so I know if something is behaving properly or not.

Thank you!