Allow parallel builds

[bigwheel]

This will resolve https://issues.jenkins-ci.org/browse/JENKINS-29696.

Thank you for help, @mimimizu.

[jenkinsadmin]

Thank you for a pull request! Please check this document for how the Jenkins project handles pull requests

[samrocketman]

Please ammend your commit message to include [JENKINS-29696]. That way the Jenkins bot posts in the issue.

[mboersma]

👍 The default serialized behavior for a post-build plugin seriously limits the throughput of our Jenkins instance. At any given moment, more than half of the "running" jobs are just waiting for a useless checkpoint on another job. Thank you for tackling this @bigwheel.

[krancour]

💯

[bigwheel]

@mboersma @samrocketman Sorry for slow response, I went summer vacation.
Thank you #122, then Should I close this pull request?

[mboersma]

@bigwheel you could fix the commit message and then I'll close #122. Or we can close this one if you prefer. Sorry to confuse things.

Note that #106 needs to be fixed before a new Slack plugin goes out, so that effectively blocks this change being released to users.

[bigwheel]

@mboersma sorry for very late response.

@bigwheel you could fix the commit message and then I'll close #122. Or we can close this one if you prefer. Sorry to confuse things.

I decide to close this PR. Thanks much support :)

[BBI-YggyKing]

I would like to get this fix, but my Jenkins doesn't see an updated version of the Slack Notification plugin yet. Should I expect to see an update soon? (Or do I need to update Jenkins itself in order to get the latest version of the Slack plugin?)

[samrocketman]

@yoyobbi the next update (of which this is included) is blocked by #106. Please feel free to contribute a fix. I only maintain pull requests and releases. I do not actively develop this plugin.

[BBI-YggyKing]

I see, understood. I haven't made the leap to Jenkins plugin development yet, so I will selfishly sit back and wait.