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.
The new "metrics" allocator is about to partition metrics and distribe
allocations among the partitions.
For example: given a region, an availability zone and free space on disk, the
allocator would be able to choose allocations by distributing among regions
and availability zones as much as possible, and for those peers in the same
region/az, selecting those with most free space first.
This requires a major overhaul of the allocator component.
i.e. a direct pin can be repinned as recursive, but a recursive
pin cannot be pinned as direct (this fails in IPFS too).
Additionally, save a couple of calls to the datastore by obtaining the
existing pin only once.
This introduces the possiblity of running Cluster with multiple informer components. The first one in the list is the used for "allocations". This is just groundwork for working with several informers in the future.
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>
This ensures that we don't re-pin something which is already correctly
pinned with the same allocations.
It also ensures that we do re-pin something when the replication
factor associated to it changes.
License: MIT
Signed-off-by: Hector Sanjuan <code@hector.link>
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>