Currently, unless doing Join() (--bootstrap), we do not connect to any peers on startup.
We however loaded up the peerstore file and Raft will automatically connect
older peers to figure out who is the leader etc. DHT bootstrap, after Raft
was working, did the rest.
For CRDTs we need to connect to people on a normal boot as otherwise, unless
bootstrapping, this does not happen, even if the peerstore contains known peers.
This introduces a number of changes:
* Move peerstore file management back inside the Cluster component, which was
already in charge of saving the peerstore file.
* We keep saving all "known addresses" but we load them with a non permanent
TTL, so that there will be clean up of peers we're not connected to for long.
* "Bootstrap" (connect) to a small number of peers during Cluster component creation.
* Bootstrap the DHT asap after this, so that other cluster components can
initialize with a working peer discovery mechanism.
* CRDT Trust() method will now:
* Protect the trusted Peer ID in the conn manager
* Give top priority in the PeerManager to that Peer (see below)
* Mark addresses as permanent in the Peerstore
The PeerManager now attaches priorities to peers when importing them and is
able to order them according to that priority. The result is that peers with
high priority are saved first in the peerstore file. When we load the peerstore
file, the first entries in it are given the highest priority.
This means that during startup we will connect to "trusted peers" first
(because they have been tagged with priority in the previous run and saved at
the top of the list). Once connected to a small number of peers, we let the
DHT bootstrap process in the background do the rest and discover the network.
All this makes the peerstore file a "bootstrap" list for CRDTs and we will attempt
to connect to peers on that list until some of those connections succeed.
This adds a new "crdt" consensus component using go-ds-crdt.
This implies several refactors to fully make cluster consensus-component
independent:
* Delete mapstate and fully adopt dsstate (after people have migrated).
* Return errors from state methods rather than ignoring them.
* Add a new "datastore" modules so that we can configure datastores in the
main configuration like other components.
* Let the consensus components fully define the "state.State". Thus, they do
not receive the state, they receive the storage where we put the state (a
go-datastore).
* Allow to customize how the monitor component obtains Peers() (the current
peerset), including avoiding using the current peerset. At the moment the
crdt consensus uses the monitoring component to define the current peerset.
Therefore the monitor component cannot rely on the consensus component to
produce a peerset.
* Re-factor/re-implementation of "ipfs-cluster-service state"
operations. Includes the dissapearance of the "migrate" one.
The CRDT consensus component defines creates a crdt-datastore (with ipfs-lite)
and uses it to intitialize a dssate. Thus the crdt-store is elegantly
wrapped. Any modifications to the state get automatically replicated to other
peers. We store all the CRDT DAG blocks in the local datastore.
The consensus components only expose a ReadOnly state, as any modifications to
the shared state should happen through them.
DHT and PubSub facilities must now be created outside of Cluster and passed in
so they can be re-used by different components.
This takes advantange of the latest features in go-cid, peer.ID and
go-multiaddr and makes the Go types serializable by default.
This means we no longer need to copy between Pin <-> PinSerial, or ID <->
IDSerial etc. We can now efficiently binary-encode these types using short
field keys and without parsing/stringifying (in many cases it just a cast).
We still get the same json output as before (with minor modifications for
Cids).
This should greatly improve Cluster performance and memory usage when dealing
with large collections of items.
License: MIT
Signed-off-by: Hector Sanjuan <hector@protocol.ai>
Additionally, remove persisting the state version to the go-datastore. In the
future versions of the state, there is not a global format anymore (with a
global version). Instead, every pin element can potentially be stored in a
different version.
License: MIT
Signed-off-by: Hector Sanjuan <hector@protocol.ai>
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 commit moves `ipfs-cluster-service` and `ipfs-cluster-ctl` to
`cmd/` directory to follow "standard" project structure.
License: MIT
Signed-off-by: Kishan Mohanbhai Sagathiya <kishansagathiya@gmail.com>
