Casting between Puppet Data Types, such as Integer("9"), will cause Puppet Server to retain Puppet::Parser::Catlog objects in memory after requests finish.
See SERVER-2874 for more context and PE reproduction case.
Reproduction Case
- Install Puppet Server on CentOS 7 along with the Java development tools:
yum install -y http://yum.puppetlabs.com/puppet6-release-el-7.noarch.rpm
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yum install -y puppetserver java-devel
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source /etc/profile.d/puppet-agent.sh
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- Install the `pupeptlabs-inifile` module and use it to enable JRuby class reification. This allows Ruby objects, like Puppet::Parser::Compiler, to be identified easily in the Java heap:
puppet module install puppetlabs-inifile
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puppet apply <<'EOF'
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ini_subsetting { 'Enable JRuby reify.classes':
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ensure => present,
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path => '/etc/sysconfig/puppetserver',
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section => '',
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key_val_separator => '=',
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setting => 'JAVA_ARGS',
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subsetting => '-Djruby.reify.classes',
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value => '=true',
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}
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EOF
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- Bootstrap the CA, configure the agent, and start the puppetserver service:
puppetserver ca setup
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puppet config set server $(hostname -f)
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systemctl start puppetserver
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- Give the service a trivial catalog to compile:
cat <<'EOF' > /etc/puppetlabs/code/environments/production/manifests/site.pp
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node default {
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$string_version = "9"
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$version = Integer($string_version)
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}
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EOF
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- Run puppet a couple of times:
puppet agent -t
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puppet agent -t
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- Check the number of Puppet::Parser::Compiler instances retained in Puppet Server memory:
sudo -u puppet jmap -histo:live $(systemctl show -p MainPID puppetserver|cut -d= -f2)|fgrep 'rubyobj.Puppet.Parser.Compiler'
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Outcome
After running the agent twice, the puppetserver service is retaining two Compiler instances in memory:
# sudo -u puppet jmap -histo:live $(systemctl show -p MainPID puppetserver|cut -d= -f2)|fgrep 'rubyobj.Puppet.Parser.Compiler'
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5871: 2 64 rubyobj.Puppet.Parser.Compiler
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Expected Outcome
No compiler instances should be retained as the compiler is discarded at the end of the request and the -histo:live flag forces a full garbage collection.
Bug
Normal
