* add final, change method permissions, add javadoc, cleanup unneeded, move updateOverallBalancingState to ClusterManagerLB and make it abstract
* Restructure to eliminate the flags as protected methods
* Move methods around so that the candidates for override are near the top.
* Reorder picker methods lower
This change has health checking consumer (new pick first) to install a listener through and health checking producer (outlier detection and client health checking) producing health checks. Health notification chain is built reusing the previous connectivity state chain.
Pickfirst installs the health listener, and is capable of detecting when no health checking producer is installed in the system. In that case, it sets health status to be READY so that health system is no-op.
We already do this for WRR. Notably, we are no longer trying to avoid
the modulus each pick. It was of questionable value, and removing it is
necessary to continue sharing the same integer when the list size
changes.
The change means we can implement a stronger isEquivalentTo() by
comparing the AtomicInteger references. It is strong enough that the
operation aligns with normal equals(). Using equals() instead of
isEquivalentTo() also made more obvious an equals() optimization that
uses the hashCode() before the more expensive HashSet creation; equals()
should now be very fast except when they are (very likely) equal.
An OutlierDetectionLoadBalancer child load balancer might decided to
shut down any subchannel it is tracking. We need to make sure that those
subchannels are removed from the outlier detection tracker map to avoid
a memory leak.
* Update picker logic per A61 that it no longer pays attention to the first 2 elements, but rather takes the first ring element not in TF and uses that.
---------
Pulled in by rebase:
Eric Anderson (android: Remove unneeded proguard rule 44723b6)
Terry Wilson (stub: Deprecate StreamObservers b5434e8)
Instead of a boolean, we now return a Status object. Status.OK
represents accepted addresses and other non-acceptance. This allows the
LB to provide more information about why a set of addresses were not
acceptable.
The status will later be sent to the name resolver as well to allow it
to also better react to to bad addresses.
FixedResultPicker can be used in more situations. Note that
WrrLocalityLoadBalancerTest's test was changed non-trivially. The
noChildLb test was particularly nasty as it assumed
LoadBalancer.ErrorPicker had same toString() as
GracefulSwitchLoadBalancer's ErrorPicker.
* Mark MultiChildLoadBalancer as Internal. Cannot move to the internal package because of its use of classes in the util package.
* Exclude MultiChildLoadBalancer from javadoc generation.
* Fix javadoc creation.
OutlierDetectionLoadBalancer did not delegate calls to an existing
ClientStreamTracer from the tracer it installed. This change has the OD
tracer delegate all calls to the underlying one.
Larry Safran
Terry Wilson
Terry Wilson
yifeizhuang
Eric Anderson
sanjaypujare