Merge "Add fallocate_reserve to account and container servers."

Code Issues Proposed changes

This commit is contained in:

Zuul

2018年07月20日 08:42:51 +00:00

committed by Gerrit Code Review

parent 791009a6ff 8e651a2d3d

commit 89854250c3

10 changed files with 321 additions and 7 deletions

@@ -298,10 +298,27 @@ Preventing Disk Full Scenarios

Prevent disk full scenarios by ensuring that the ``proxy-server`` blocks PUT

requests and rsync prevents replication to the specific drives.

You can prevent `proxy-server` PUT requests to low space disks by ensuring

``fallocate_reserve`` is set in the ``object-server.conf``. By default,

``fallocate_reserve`` is set to 1%. This blocks PUT requests that leave the

free disk space below 1% of the disk.

You can prevent `proxy-server` PUT requests to low space disks by

ensuring ``fallocate_reserve`` is set in ``account-server.conf``,

``container-server.conf``, and ``object-server.conf``. By default,

``fallocate_reserve`` is set to 1%. In the object server, this blocks

PUT requests that would leave the free disk space below 1% of the

disk. In the account and container servers, this blocks operations

that will increase account or container database size once the free

disk space falls below 1%.

Setting ``fallocate_reserve`` is highly recommended to avoid filling

disks to 100%. When Swift's disks are completely full, all requests

involving those disks will fail, including DELETE requests that would

otherwise free up space. This is because object deletion includes the

creation of a zero-byte tombstone (.ts) to record the time of the

deletion for replication purposes; this happens prior to deletion of

the object's data. On a completely-full filesystem, that zero-byte .ts

file cannot be created, so the DELETE request will fail and the disk

will remain completely full. If ``fallocate_reserve`` is set, then the

filesystem will have enough space to create the zero-byte .ts file,

and thus the deletion of the object will succeed and free up some

space.

In order to prevent rsync replication to specific drives, firstly

setup ``rsync_module`` per disk in your ``object-replicator``.