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 uses go-libp2p-kad-dht as routing provider for the Cluster Peers.
This means that:
* A cluster peer can discover other Cluster peers even if they are
not in their peerstore file.
* We remove a bunch of code sending and receiving peers multiaddresses
when a new peer was added to the Cluster.
* PeerAdd now takes an ID and not a multiaddress. We do not need to
ask the new peer which is our external multiaddress nor broadcast
the new multiaddress to everyone. This will fix problems when bootstrapping
a new peer to the Cluster while not all the other peers are online.
* Adding a new peer does not mean to open connections to all peers
anymore. The number of connections will be made according to the DHT
parameters (this is good to have for future work)
The that detecting a peer addition in the watchPeers() function does
no longer mean that we have connected to it or that we know its
multiaddresses. Therefore it's no point to save the peerstore in these
events anymore.
Here a question opens, should we save the peerstore at all, and should we
save multiaddresses only for cluster peers, or for everyone known?
Currently, the peerstore is only updated on clean shutdown,
and it is updated with all the multiaddresses known, and not limited to
peer IDs in the cluster, (because, why not).
License: MIT
Signed-off-by: Hector Sanjuan <code@hector.link>
