After deleting an object, the object expirer deletes the corresponding
row from the expirer queue by making DELETE requests directly to the
container servers. The same thing happens after attempting to delete
an object, but failing because the object has already been deleted. If
the DELETE requests fail, then the expirer will encounter that row
again on its next pass and retry the DELETE at that time. Therefore,
it is not necessary for the object server to write an async_pending
for that queue row's deletion.
Currently, however, two of the object servers do write such
async_pendings. Given Rc container replicas, that's 2 * Rc updates
from async_pendings and another Rc from the object expirer
directly. Given a typical Rc of 3, that's 9 container updates per
expiring object.
This commit makes the object server write no async_pendings for DELETE
requests coming from the object expirer. This reduces the number of
container server requests to Rc (typically 3), all issued directly
from the object expirer.
Closes-Bug: 1076202
Change-Id: Icd63c80c73f864d2561e745c3154fbfda02bd0cc
745581ff2f