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.
http.Transport keeps a pool of connections and should be reused when possible. We instantiate a new http.DefaultTransport for every metrics request, making large numbers of concurrent requests inefficiently spin up new connections instead of reusing open ones.
When a sidecar proxy is registered, a check is automatically added.
Previously, the address this check used was the underlying service's
address instead of the proxy's address, even though the check is testing
if the proxy is up.
This worked in most cases because the proxy ran on the same IP as the
underlying service but it's not guaranteed and so the proper default
address should be the proxy's address.
* draft commit
* add changelog, update test
* remove extra param
* fix test
* update type to account for nil value
* add test for custom passive health check
* update comments and tests
* update description in docs
* fix missing commas
* validate args before deleting proxy defaults
* add changelog
* validate name when normalizing proxy defaults
* add test for proxyConfigEntry
* add comments
`QueryDatacenterOptions` was renamed to `QueryFailoverOptions` without creating
an alias. This adds `QueryDatacenterOptions` back as an alias to
`QueryFailoverOptions` and marks it is deprecated.
Consul 1.13.0 changed ServiceVirtualIP to use PeeredServiceName instead of ServiceName which was a breaking change for those using service mesh and wanted to restore their snapshot after upgrading to 1.13.0.
This commit handles existing data with older ServiceName and converts it during restore so that there are no issues when restoring from older snapshots.
1. Create a bexpr filter for performing the filtering
2. Change the state store functions to return the raw (not aggregated)
list of ServiceNodes.
3. Move the aggregate service tags by name logic out of the state store
functions into a new function called from the RPC endpoint
4. Perform the filtering in the endpoint before aggregation.
If startListeners successfully created listeners for some of its input addresses but eventually failed, the function would return an error and existing listeners would not be cleaned up.
Previously, when launching a sidecar proxy with one of the following commands:
- consul connect envoy -sidecar-for=...
- consul connect proxy -sidecar-for=...
... the -sidecar-for argument could only contain lowercase letters, even if
the service was registered with some uppercase letters.
Now, the -sidecar-for argument is treated as case-insensitive.
Dan Upton