This patch changes the default model—where confd is always started in
polling mode—to a model where if possible we enable inotify mode
before starting any of the background threads.
There are some tricky details here: if we enable inotify, we should
not modify the server state after wards, as inotify events could have
already fired and took ownership; therefore we presume that inotify
will work and set reloadModel=ReloadNotify, and only if we fail to
enable it we change it back to polling mode.
Signed-off-by: Iustin Pop <ius...@google.com>
---
src/Ganeti/Confd/Server.hs | 27 ++++++++++++++++++++-------
1 file changed, 20 insertions(+), 7 deletions(-)
diff --git a/src/Ganeti/Confd/Server.hs b/src/Ganeti/Confd/Server.hs
index 29204a4..46f7226 100644
--- a/src/Ganeti/Confd/Server.hs
+++ b/src/Ganeti/Confd/Server.hs
@@ -33,7 +33,7 @@ module Ganeti.Confd.Server
import Control.Concurrent
import Control.Exception
-import Control.Monad (forever, liftM, when)
+import Control.Monad (forever, liftM, when, unless)
import Data.IORef
import Data.List
import qualified Data.Map as M
@@ -112,6 +112,7 @@ initialPoll = ReloadPoll 0
data ConfigReload = ConfigToDate -- ^ No need to reload
| ConfigReloaded -- ^ Configuration reloaded
| ConfigIOError -- ^ Error during configuration reload
+ deriving (Eq)
-- | Unknown entry standard response.
queryUnknownEntry :: StatusAnswer
@@ -522,19 +523,31 @@ prepMain _ (af_family, bindaddr) = do
-- | Main function.
main :: MainFn (S.Family, S.SockAddr) PrepResult
main _ _ (s, query_data, cref) = do
+ -- Inotify setup
+ inotify <- initINotify
-- try to load the configuration, if possible
conf_file <- Path.clusterConfFile
- (fstat, _) <- safeUpdateConfig conf_file nullFStat cref
+ (fstat, reloaded) <- safeUpdateConfig conf_file nullFStat cref
ctime <- getCurrentTime
- statemvar <- newMVar $ ServerState initialPoll ctime fstat
- hmac <- getClusterHmac
- -- Inotify setup
- inotify <- initINotify
+ statemvar <- newMVar $ ServerState ReloadNotify ctime fstat
let inotiaction = addNotifier inotify conf_file cref statemvar
+ has_inoti <- if reloaded == ConfigReloaded
+ then inotiaction
+ else return False
+ if has_inoti
+ then logInfo "Starting up in inotify mode"
+ else do
+ -- inotify was not enabled, we need to update the reload model
+ logInfo "Starting up in polling mode"
+ modifyMVar_ statemvar
+ (\state -> return state { reloadModel = initialPoll })
+ hmac <- getClusterHmac
-- fork the timeout timer
_ <- forkIO $ onTimeoutTimer inotiaction conf_file cref statemvar
-- fork the polling timer
- _ <- forkIO $ onReloadTimer inotiaction conf_file cref statemvar
+ unless has_inoti $ do
+ _ <- forkIO $ onReloadTimer inotiaction conf_file cref statemvar
+ return ()
-- launch the queryd listener
_ <- forkIO $ runQueryD query_data (configReader cref)
-- and finally enter the responder loop
--
1.7.10.4
