This commit adds a monotonically increasing nonce to include in peering
replication response messages. Every ack/nack from the peer handling a
response will include this nonce, allowing to correlate the ack/nack
with a specific resource.
At the moment nothing is done with the nonce when it is received. In the
future we may want to add functionality such as retries on NACKs,
depending on the class of error.
* Move stats.go from grpc-internal to grpc-middleware
* Update grpc server metrics with server type label
* Add stats test to grpc-external
* Remove global metrics instance from grpc server tests
This commit adds handling so that the replication stream considers
whether the user intends to peer through mesh gateways.
The subscription will return server or mesh gateway addresses depending
on the mesh configuration setting. These watches can be updated at
runtime by modifying the mesh config entry.
Prior to #13244, connect proxies and gateways could only be configured by an
xDS session served by the local client agent.
In an upcoming release, it will be possible to deploy a Consul service mesh
without client agents. In this model, xDS sessions will be handled by the
servers themselves, which necessitates load-balancing to prevent a single
server from receiving a disproportionate amount of load and becoming
overwhelmed.
This introduces a simple form of load-balancing where Consul will attempt to
achieve an even spread of load (xDS sessions) between all healthy servers.
It does so by implementing a concurrent session limiter (limiter.SessionLimiter)
and adjusting the limit according to autopilot state and proxy service
registrations in the catalog.
If a server is already over capacity (i.e. the session limit is lowered),
Consul will begin draining sessions to rebalance the load. This will result
in the client receiving a `RESOURCE_EXHAUSTED` status code. It is the client's
responsibility to observe this response and reconnect to a different server.
Users of the gRPC client connection brokered by the
consul-server-connection-manager library will get this for free.
The rate at which Consul will drain sessions to rebalance load is scaled
dynamically based on the number of proxies in the catalog.
To ease the transition for users, the original gRPC
port can still operate in a deprecated mode as either
plain-text or TLS mode. This behavior should be removed
in a future release whenever we no longer support this.
The resulting behavior from this commit is:
`ports.grpc > 0 && ports.grpc_tls > 0` spawns both plain-text and tls ports.
`ports.grpc > 0 && grpc.tls == undefined` spawns a single plain-text port.
`ports.grpc > 0 && grpc.tls != undefined` spawns a single tls port (backwards compat mode).
Contains 2 changes to the GetEnvoyBootstrapParams response to support
consul-dataplane.
Exposing node_name and node_id:
consul-dataplane will support providing either the node_id or node_name in its
configuration. Unfortunately, supporting both in the xDS meta adds a fair amount
of complexity (partly because most tables are currently indexed on node_name)
so for now we're going to return them both from the bootstrap params endpoint,
allowing consul-dataplane to exchange a node_id for a node_name (which it will
supply in the xDS meta).
Properly setting service for gateways:
To avoid the need to special case gateways in consul-dataplane, service will now
either be the destination service name for connect proxies, or the gateway
service name. This means it can be used as-is in Envoy configuration (i.e. as a
cluster name or in metric tags).
newMockSnapshotHandler has an assertion on t.Cleanup which gets called before the event publisher is cancelled. This commit reorders the context.WithCancel so it properly gets cancelled before the assertion is made.
Freddy