Avoid waiting for a double notification once a node rejoin, just
put it back to active state. Waiting for a further message does not
really add anything to the safety of the operation, the source of truth
for the node status resided inside memberlist.
Signed-off-by: Flavio Crisciani <flavio.crisciani@docker.com>
Created method to handle the node state change with cleanup operation
associated.
Realign testing client with the new diagnostic interface
Signed-off-by: Flavio Crisciani <flavio.crisciani@docker.com>
If a node leave, avoid to notify the upper layer
for entries that are already marked for deletion
Signed-off-by: Flavio Crisciani <flavio.crisciani@docker.com>
The previous logic was not properly handling the case of a node
that was failing and oining back in short period of time.
The issue was in the handling of the network messages.
When a node joins it sync with other nodes, these are passing
the whole list of nodes that at best of their knowledge are part
of a network. At this point if the node receives that node A is part
of the network it saves it before having received the notification
that node A is actually alive (coming from memberlist).
If node A failed the source node will receive the notification
while the new joined node won't because memberlist never advertise
node A as available. In this case the new node will never purge
node A from its state but also worse, will accept any table notification
where node A is the owner and so will end up in a out of sync state
with the rest of the cluster.
This commit contains also some code cleanup around the area of node
management
Signed-off-by: Flavio Crisciani <flavio.crisciani@docker.com>
Before when a node was failing, all the nodes would bump the lamport time of all their
entries. This means that if a node flap, there will be a storm of update of all the entries.
This commit on the base of the previous logic guarantees that only the node that joins back
will readvertise its own entries, the other nodes won't need to advertise again.
Signed-off-by: Flavio Crisciani <flavio.crisciani@docker.com>
The time to keep a node failed into the failed node list
was originally supposed to be 24h.
If a node leaves explicitly it will be removed from the list of nodes
and put into the leftNodes list. This way the NotifyLeave event won't
insert it into the retry list.
NOTE: if the event is lost instead the behavior will be the same as a failed node.
If a node fails, the NotifyLeave will insert it into the failedNodes
list with a reapTime of 24h. This means that the node will be checked
for 24h before being completely forgot. The current check time is every
1 second and is done by the reconnectNode function.
The failed node list is updated every 2h instead.
Signed-off-by: Flavio Crisciani <flavio.crisciani@docker.com>
With the introduction of networkdb, the node discovery events were not
sent to the drivers. This commit generates the node discovery events and
sents it to the drivers interested in it.
Signed-off-by: Madhu Venugopal <madhu@docker.com>
Currently if there is any transient gossip failure in any node the
recoevry process depends on other nodes propogating the information
indirectly. In cases if these transient failures affects all the nodes
that this node has in its memberlist then this node will be permenantly
cutoff from the the gossip channel. Added node state management code in
networkdb to address these problems by trying to rejoin the cluster via
the failed nodes when there is a failure. This also necessitates the
need to add new messages called node event messages to differentiate
between node leave and node failure.
Signed-off-by: Jana Radhakrishnan <mrjana@docker.com>
When a node goes away purge all the network attachments from the node
and make sure we don't attempt bulk syncing to that node once removed.
Signed-off-by: Jana Radhakrishnan <mrjana@docker.com>
Network DB is a network scoped gossip database built
on top of hashicorp/memberlist providing an eventually
consistent state store.
It limits the scope of the gossip and periodic bulk syncing
for table entries to only the nodes which participate in the
network to which the gossip belongs. This designs make the
gossip layer scale better and only consumes resources for the
network state that the node participates in.
Since the complete state for a network is maintained by all nodes
participating in the network, all nodes will eventually converge
to the same state.
NetworkDB also provides facilities for the users of the package to
watch on any table (or all tables) and get notified if there are
state changes of interest that happened anywhere in the cluster when
that state change eventually finds it's way to the watcher's node.
Signed-off-by: Jana Radhakrishnan <mrjana@docker.com>
