Since the beginning, we have used a Go map to store the shared state (pinset)
in memory. The mapstate knew how to serialize itself so that libp2p-raft would
know how to write to disk when it:
* Saved snapshots of the state on shutdown
* Sent the state to a newcomer peer
hashicorp.Raft assumes an in-memory state which is snapshotted from time to
time and read from disk on boot.
This commit adds a `dsstate` implementation of the state interface using
`go-datastore`. This allows to effortlessly switch to a disk-backed state in
the future (as we will need), and also have at our disposal the different
implementations and utilities of Datastore for fine-tuning (caching, batching
etc.).
`mapstate` has been reworked to use dsstate. Ideally, we would not even need
`mapstate`, as it would suffice to initialize `dsstate` with a
`MapDatastore`. BUT, we still need it separate to be able to auto-migrate to
the new format.
This will be the last migration with the current system. Once this has been
released and users have been able to upgrade we will just remove `mapstate` as
it is now.
License: MIT
Signed-off-by: Hector Sanjuan <code@hector.link>
This commit adds support for OpenCensus tracing
and metrics collection. This required support for
context.Context propogation throughout the cluster
codebase, and in particular, the ipfscluster component
interfaces.
The tracing propogates across RPC and HTTP boundaries.
The current default tracing backend is Jaeger.
The metrics currently exports the metrics exposed by
the opencensus http plugin as well as the pprof metrics
to a prometheus endpoint for scraping.
The current default metrics backend is Prometheus.
Metrics are currently exposed by default due to low
overhead, can be turned off if desired, whereas tracing
is off by default as it has a much higher performance
overhead, though the extent of the performance hit can be
adjusted with smaller sampling rates.
License: MIT
Signed-off-by: Adrian Lanzafame <adrianlanzafame92@gmail.com>
This PR replaces ReplicationFactor with ReplicationFactorMax
and ReplicationFactor min.
This allows a CID to be pinned even though the desired
replication factor (max) is not reached, and prevents triggering
re-pinnings when the replication factor has not crossed the
lower threshold (min).
License: MIT
Signed-off-by: Hector Sanjuan <code@hector.link>
ipfs-cluster-service now has a migration subcommand that upgrades
persistant state snapshots with an out-of-date format version to the
newest version of raft state. If all cluster members shutdown with
consistent state, upgrade ipfs-cluster, and run the state upgrade command,
the new version of cluster will be compatible with persistent storage.
ipfs-cluster now validates its persistent state upon loading it and exits
with a clear error in the case the state format version is not up to date.
Raft snapshotting is enforced on all shutdowns and the json backup is no
longer run. This commit makes use of recent changes to libp2p-raft
allowing raft states to implement their own marshaling strategies. Now
mapstate handles the logic for its (de)serialization. In the interest of
supporting various potential upgrade formats the state serialization
begins with a varint (right now one byte) describing the version.
Some go tests are modified and a go test is added to cover new ipfs-cluster
raft snapshot reading functions. Sharness tests are added to cover the
state upgrade command.
This adds snapshot and restore methods to state and uses the snapshot
one to save a copy of the state when shutting down. Right now, this is
not used for anything else.
Some lines performing a migration, but this is only an idea of how it could
work.
License: MIT
Signed-off-by: Hector Sanjuan <hector@protocol.ai>
This adds a replication_factor query argument to the API
endpoint which allows to set a replication factor per Pin.
License: MIT
Signed-off-by: Hector Sanjuan <hector@protocol.ai>
CidArg used to be an internal name for an argument that carried a Cid.
Now it has surfaced to API level and makes no sense. It is a Pin. It
represents a Pin (Cid, Allocations, Replication Factor)
License: MIT
Signed-off-by: Hector Sanjuan <hector@protocol.ai>
New PeerManager, Allocator, Informer components have been added along
with a new "replication_factor" configuration option.
First, cluster peers collect and push metrics (Informer) to the Cluster
leader regularly. The Informer is an interface that can be implemented
in custom wayts to support custom metrics.
Second, on a pin operation, using the information from the collected metrics,
an Allocator can provide a list of preferences as to where the new pin
should be assigned. The Allocator is an interface allowing to provide
different allocation strategies.
Both Allocator and Informer are Cluster Componenets, and have access
to the RPC API.
The allocations are kept in the shared state. Cluster peer failure
detection is still missing and re-allocation is still missing, although
re-pinning something when a node is down/metrics missing does re-allocate
the pin somewhere else.
License: MIT
Signed-off-by: Hector Sanjuan <hector@protocol.ai>
