Prevent init script from returning when the service isn't actually started #6909
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@spinscale please could you take a look |
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With all the tests i do with the packages and init scripts i have never seen this sort of race condition happen. |
| i=0 | ||
| timeout=10 | ||
| # Wait for the process to be properly started before exiting | ||
| until { cat "$PID_FILE" | xargs kill -0; } >/dev/null 2>&1 |
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This line seems weird to me. You're sending a kill -0 signal to check if a process with the PID exists, but the PID_FILE will only exist if the process has started because it is that process which writes the PID_FILE... What are you trying to achieve here?
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If the PID file doesn't exist, xargs kill returns 123 so the loop keeps going.
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@sbraz Have you seen this problem occur, or is this a theoretical concern? |
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I have seen it occur when I started ElasticSearch with Pacemaker, it would sometimes start ES, check its status and find it stopped. |
…sn't actually started. Close #6909
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Sorry for the delay, but I just merged this PR. Thanks! |
Hello,
Since the init script uses start-stop-daemon's
-boption, it might return from start before the service is actually started. If the init script's status action is called immediately after that, It will returnelasticsearch is not runningand exit with a non-zero code.This causes systems like Heartbeat to incorrectly start multiple instances of Elasticsearch at once.
This pull request aims at fixing this issue by waiting until the Elasticsearch process is started.
There might be a nicer way to achieve this but this is what came to mind.