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author | 2018-01-04 13:43:33 +0800 | |
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committer | 2018-01-05 11:59:39 +0800 | |
commit | 812ff6ca9fcd3e629e49d4328905f33eee8ca3f5 (patch) | |
tree | 04ece7b4da00d9d2f98093774594f4057ae561d4 /src/ceph/doc/dev/osd_internals/pg.rst | |
parent | 15280273faafb77777eab341909a3f495cf248d9 (diff) |
initial code repo
This patch creates initial code repo.
For ceph, luminous stable release will be used for base code,
and next changes and optimization for ceph will be added to it.
For opensds, currently any changes can be upstreamed into original
opensds repo (https://github.com/opensds/opensds), and so stor4nfv
will directly clone opensds code to deploy stor4nfv environment.
And the scripts for deployment based on ceph and opensds will be
put into 'ci' directory.
Change-Id: I46a32218884c75dda2936337604ff03c554648e4
Signed-off-by: Qiaowei Ren <qiaowei.ren@intel.com>
Diffstat (limited to 'src/ceph/doc/dev/osd_internals/pg.rst')
-rw-r--r-- | src/ceph/doc/dev/osd_internals/pg.rst | 31 |
1 files changed, 31 insertions, 0 deletions
diff --git a/src/ceph/doc/dev/osd_internals/pg.rst b/src/ceph/doc/dev/osd_internals/pg.rst new file mode 100644 index 0000000..4055363 --- /dev/null +++ b/src/ceph/doc/dev/osd_internals/pg.rst @@ -0,0 +1,31 @@ +==== +PG +==== + +Concepts +-------- + +*Peering Interval* + See PG::start_peering_interval. + See PG::acting_up_affected + See PG::RecoveryState::Reset + + A peering interval is a maximal set of contiguous map epochs in which the + up and acting sets did not change. PG::RecoveryMachine represents a + transition from one interval to another as passing through + RecoveryState::Reset. On PG::RecoveryState::AdvMap PG::acting_up_affected can + cause the pg to transition to Reset. + + +Peering Details and Gotchas +--------------------------- +For an overview of peering, see `Peering <../../peering>`_. + + * PG::flushed defaults to false and is set to false in + PG::start_peering_interval. Upon transitioning to PG::RecoveryState::Started + we send a transaction through the pg op sequencer which, upon complete, + sends a FlushedEvt which sets flushed to true. The primary cannot go + active until this happens (See PG::RecoveryState::WaitFlushedPeering). + Replicas can go active but cannot serve ops (writes or reads). + This is necessary because we cannot read our ondisk state until unstable + transactions from the previous interval have cleared. |