Lockless code deploys
The lockless code deploys feature within Code Manager allows deployment of Puppet code without interrupting other Puppet operations. When this feature is disabled, requests to Puppet Server are blocked during code deployments until the file sync client has finished updating the live Puppet code directory, However, when lockless code deploys are enabled, the file sync client saves newly deployed code into versioned directories, ensuring that the live code directory is not overwritten. This process allows Puppet operations to continue without interruption during code deployments.
/opt/puppetlabs/server/data/puppetserver/filesync/client/versioned-dirs/puppet-code/
When the feature is enabled, the Puppet Server code directory is
set up at /etc/puppetlabs/puppetserver/code
and points,
via symlink, to the most recent versioned code directory (at the versioned directories
filepath specified above). If you disable lockless deploys, your code directory moves to
/etc/puppetlabs/code
.
Lockless deploys enable you to deploy a new version of code alongside an old version.
When a catalog compiles starts, it uses the full path to the most recent version of code
in the versioned code directory (via the /etc/puppetlabs/puppetserver/code
symlink). Existing catalog compiles
continue using the version they started on and new compiles use the latest code
version.
To conserve disk space, code written to versioned directories is optimized to reduce
duplication, and directories older than the latest and its predecessor are cleaned up
after 30 minutes. If you deploy code very frequently, you might prefer to decrease the
versioned-dirs-ttl
setting, which is specified, in
minutes, in file-sync.conf
within each file sync
client.
System requirements for lockless deploys
Enabling lockless deploys increases the disk storage required on your primary server and compilers because code is written to multiple versioned directories, instead of a single live code directory. Follow these guidelines for estimating your required system capacity.
(Size of typical environment)×(Number of active environments)
For
example, if your typical environment is 200 MB on disk when deployed, and you have 25
active environments, your disk storage calculation is 200 MB ×
25
, which equals 5,000 MB or 5 GB.(Size of typical environment × .25)×(Number of environments deployed multiple times per day)×(Number of deployments per day)
Continuing
the previous example, if 6 of your 200 MB environments are deployed up to 10 times per
day, your additional disk storage calculation is (200 MB × .25) ×
6 × 10
, which equals 3,000 MB or 3 GB of additional disk space. In total,
this example requires 8 GB available for your primary server and each compiler.Toggle lockless code deploys on or off
Use the toggle_lockless_deploys
plan to turn lockless code deploys
on or off across all compiler nodes, including the primary server and the
replica.
toggle_lockless_deploys
plan by running these
commands on the primary server:- To enable lockless code
deploys:
puppet infra run toggle_lockless_deploys enable=true
- To disable lockless code
deploys:
If you do not specifypuppet infra run toggle_lockless_deploys enable=false
true
orfalse
,true
is the default. - Optionally, you can use the
old_code_directory
parameter with either thesave
ordelete
values, to specify whether you want to save old code directories to${codedir}_backup
. For example:
If you do not specify thepuppet infra run toggle_lockless_deploys enable=true old_code_directory=save
old_code_directory
parameter,save
is set by default.
The toggle_lockless_deploys
plan does not
properly switch over a replica in disaster recovery to have lockless deploys because
doing so requires updating Hiera data. Users who already have disaster recovery
enabled and are toggling lockless deploys are recommended to update their pe.conf
after running the plan. While polling for
changes, do not prematurely abort the toggle_lockless_deploys
plan run if you see errors on the console.
Wait until the plan fully completes before assessing whether the failures were an
expected part of polling for changes or not.
Enable lockless code deploys on one compiler
Use these steps to enable lockless code deploys on one Puppet Server instance.
toggle_lockless_deploys
plan. Or you might
want to enable lockless code deploys on an individual compiler for testing, before you
enable the feature across all compiler nodes.