Add a connection timeout for remote region connections

[carbonin]

This will prevent a non-responsive remote region from hanging
the UI when trying to query for the replication backlog.

Regular ruby Timeout won't work here because the PG connection code
doesn't respond to the exception until after it has exhausted the
underlying libpq timeout logic.

Fixes https://bugzilla.redhat.com/show_bug.cgi?id=1796681

[miq-bot]

Checked commit carbonin@8098b63 with ruby 2.5.5, rubocop 0.69.0, haml-lint 0.20.0, and yamllint 1.10.0
2 files checked, 1 offense detected

app/models/pglogical_subscription.rb

• ❗ - Line 264, Col 39 - Style/SymbolProc - Pass &:xlog_location as an argument to with_remote_connection instead of a block.

[jrafanie]

LGTM. @carbonin do we need to handle this connection timeout differently? In other words, where we'd normally have a regular connection with what I presume is an infinite connection timeout only limited by lower transport layers in the PG gem itself, we'll now have a 5 second timeout whenever we use a remote connection. Will it raise like a normal ruby timeout?

[carbonin]

Will it raise like a normal ruby timeout?

It will raise, but not a Timeout::Error. It will be a kind of PG::Error. I'm not sure what class exactly.

[jrafanie]

Will it raise like a normal ruby timeout?

It will raise, but not a Timeout::Error. It will be a kind of PG::Error. I'm not sure what class exactly.

Ok, it looks like we ensure around it so it should "ensure" even Exception/non-standard error types will be removed.

[simaishi]

Hammer backport details:

$ git log -1
commit 9e115d9675885ff7749a50983049dba7406cfbe6
Author: Joe Rafaniello <[email protected]>
Date:   Tue Feb 4 16:09:22 2020 -0500

    Merge pull request #19791 from carbonin/add_timeout_to_remote_region_connection

    Add a connection timeout for remote region connections

    (cherry picked from commit 3394f484299fd00abedb006811196e8be5e8a723)

    Fixes https://bugzilla.redhat.com/show_bug.cgi?id=1798523

[carbonin]

@simaishi can this be backported to ivanchuk as well? Do you need to me to do something for that?

[simaishi]

@carbonin Nothing is needed from you. This will be backported when we start working on the next release.

[simaishi]

Ivanchuk backport details:

$ git log -1
commit b4969358c4f93e59c54d2a6edb0d2db13699a244
Author: Joe Rafaniello <[email protected]>
Date:   Tue Feb 4 16:09:22 2020 -0500

    Merge pull request #19791 from carbonin/add_timeout_to_remote_region_connection

    Add a connection timeout for remote region connections

    (cherry picked from commit 3394f484299fd00abedb006811196e8be5e8a723)

    Fixes https://bugzilla.redhat.com/show_bug.cgi?id=1798526