topic Re: Trident - Snapshots and Quiescing in Software Development Kit (SDK) and API Discussions

Trident - Snapshots and Quiescing

bcoy — Tue, 08 Jan 2019 20:18:56 GMT

How does DB quiescing work within a container using Trident?

Re: Trident - Snapshots and Quiescing

olivpass — Tue, 19 Jan 2021 13:11:10 GMT

Hi bcoy,

do you have an answer for this?

i have an idea how to do this, but it is not fully ready:

* it is possible to create a snapshot and a new volume from a volume with one docker command:
** docker volume create --driver drivername --name volume_name_quiesced_snap -o from=volume_name

The flow to get a quiesed snapshot will this:

1 quiesce the db

2 docker volume create --driver drivername --name dbvolume_name_quiesced_snap -o from=dbvolume_name

3 unquiesce the db

Re: Trident - Snapshots and Quiescing

elementx — Wed, 20 Jan 2021 01:14:05 GMT

It works the same way as with VMs and bare metal servers, i.e. the snapshot feature doesn't do it.

Like with the other two you need to quiesce the DB if you want transaction-consistent snapshots, or just ignore the quiesce step and use crash-cosnistent snapshots.

Some people say crash-consistent snapshots aren't reliable, but if your database cannot survive OS crash, maybe you should change or upgrade your database application...