From 19fcec84d8d7d21e796c7624e521b60d28ee21ed Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Sun, 7 Apr 2024 20:45:59 +0200 Subject: Adding upstream version 16.2.11+ds. Signed-off-by: Daniel Baumann --- doc/dev/osd_internals/pg.rst | 31 +++++++++++++++++++++++++++++++ 1 file changed, 31 insertions(+) create mode 100644 doc/dev/osd_internals/pg.rst (limited to 'doc/dev/osd_internals/pg.rst') diff --git a/doc/dev/osd_internals/pg.rst b/doc/dev/osd_internals/pg.rst new file mode 100644 index 000000000..397d4ab5d --- /dev/null +++ b/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::PeeringState::Reset + + A peering interval is a maximal set of contiguous map epochs in which the + up and acting sets did not change. PG::PeeringMachine represents a + transition from one interval to another as passing through + PeeringState::Reset. On PG::PeeringState::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::PeeringState::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::PeeringState::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. -- cgit v1.2.3