This commit introduces the new go-libp2p-gorpc streaming capabilities for
Cluster. The main aim is to work towards heavily reducing memory usage when
working with very large pinsets.
As a side-effect, it takes the chance to revampt all types for all public
methods so that pointers to static what should be static objects are not used
anymore. This should heavily reduce heap allocations and GC activity.
The main change is that state.List now returns a channel from which to read
the pins, rather than pins being all loaded into a huge slice.
Things reading pins have been all updated to iterate on the channel rather
than on the slice. The full pinset is no longer fully loaded onto memory for
things that run regularly like StateSync().
Additionally, the /allocations endpoint of the rest API no longer returns an
array of pins, but rather streams json-encoded pin objects directly. This
change has extended to the restapi client (which puts pins into a channel as
they arrive) and to ipfs-cluster-ctl.
There are still pending improvements like StatusAll() calls which should also
stream responses, and specially BlockPut calls which should stream blocks
directly into IPFS on a single call.
These are coming up in future commits.
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>
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>
