Fingerprinting the config is somewhat brittle -- it requires either
custom bootstrapping for old (fingerprint-less) configs, and may have
false-positives.
Since generating the config is lightweight, do so into the .tmp files,
and compare the output to the originals to determine if there are
changes to apply.
In order to both surface errors, as well as notify the user in case a
restart is necessary, we must run it twice. The `onlyif`
functionality cannot show configuration errors to the user, only
determine if the command runs or not. We thus run the command once,
judging errors as "interesting" enough to run the actual command,
whose failure will be verbose in Puppet and halt any steps that depend
on it.
Removing the `onlyif` would result in `stage_updated_sharding` showing
up in the output of every Puppet run, which obscures the important
messages it displays when an update to sharding is necessary.
Removing the `command` (e.g. making it an `echo`) would result in
removing the ability to report configuration errors. We thus have no
choice but to run it twice; this is thankfully low-overhead.
We can compute the intended number of processes from the sharding
configuration. In doing so, also validate that all of the ports are
contiguous.
This removes a discrepancy between `scripts/lib/sharding.py` and other
parts of the codebase about if merely having a `[tornado_sharding]`
section is sufficient to enable sharding. Having behaviour which
changes merely based on if an empty section exists is surprising.
This does require that a (presumably empty) `9800` configuration line
exist, but making that default explicit is useful.
After this commit, configuring sharding can be done by adding to
`zulip.conf`:
```
[tornado_sharding]
9800 = # default
9801 = other_realm
```
Followed by running `./scripts/refresh-sharding-and-restart`.
This supports running puppet to pick up new sharding changes, which
will warn of the need to finalize them via
`refresh-sharding-and-restart`, or simply running that directly.
Generated by pyupgrade --py36-plus --keep-percent-format.
Now including %d, %i, %u, and multi-line strings.
Signed-off-by: Anders Kaseorg <anders@zulip.com>
Fixes#2665.
Regenerated by tabbott with `lint --fix` after a rebase and change in
parameters.
Note from tabbott: In a few cases, this converts technical debt in the
form of unsorted imports into different technical debt in the form of
our largest files having very long, ugly import sequences at the
start. I expect this change will increase pressure for us to split
those files, which isn't a bad thing.
Signed-off-by: Anders Kaseorg <anders@zulip.com>
Generated by pyupgrade --py36-plus --keep-percent-format, but with the
NamedTuple changes reverted (see commit
ba7906a3c6, #15132).
Signed-off-by: Anders Kaseorg <anders@zulip.com>
This allows straight-forward configuration of realm-based Tornado
sharding through simply editing /etc/zulip/zulip.conf to configure
shards and running scripts/refresh-sharding-and-restart.
Co-Author-By: Mateusz Mandera <mateusz.mandera@zulip.com>
Anders Kaseorg
Alex Vandiver
Tim Abbott