Add a new role for ratekeeper.
Remove StorageServerChanges from data distribution.
Ratekeeper monitors storage servers, which borrows the idea from
DataDistribution.
Let cluster controller to start a new data distributor role by sending a
message to a chosen worker.
Change MasterInterface usage in DataDistribution to masterId
Add DataDistributor rejoin handling.
This allows the data distributor to tell the new cluster controller of its
existence so that the controller doesn't spawn a new one. I.e., there should
be only ONE data distributor in the cluster.
If DataDistributor (DD) doesn't join in a while, then ClusterController (CC) tries
to recruit one as DD. CC also monitors DD and restarts one if it failed.
The Proxy is also monitoring the DD. If DD failed, the Proxy will ask CC for
the new DD.
Add GetRecoveryInfo RPC to master server, which is called by data distributor
to obtain the recovery Transaction version from the master server.
Remove the use of relative paths. A header at foo/bar.h could be included by
files under foo/ with "bar.h", but would be included everywhere else as
"foo/bar.h". Adjust so that every include references such a header with the
latter form.
Signed-off-by: Robert Escriva <rescriva@dropbox.com>
The previous order of fitness was
BestFit > GoodFit > BestOtherFit > ...
which is baffling. It's now:
BestFit > GoodFit > OkayFit > ...
which won't break anyone's expectations.
added configuration options for the remote data center and satellite data centers
updated cluster controller recruitment logic
refactors how master writes core state
updated log recovery, and log system peeking
Alex Miller