Although the existing code wasn't causing a deadlock or causing
goroutines to hang forever, this is cleaner and prevents any such thing
from happening in the future.
Small refactor of tests:
- Add a channel to remoteBalancer on which to send received stats messages
- Change runAndGetStats to runAndCheckStats to allow for faster successful test
runs (no longer need to sleep for one whole second per test).
- Remove redundant leak check from runAndCheckStats, otherwise excess load
report messages not read from the channel will result in an infinite loop.
- Add String method to rpcStats to avoid data race between merging and printing.
The client will send a request with version/nonce after receiving a
response, to ack/nack.
Ack versions for different xds types are independent.
Some other changes
- merge sendRequests to one shared function, with fields for version/nonce
- deleted enum for xds types, and always use const URL string
Errors will be handled specifically, depending on whether it's a
connection error or other types of errors.
Without this fix, balancer's callback will be called with <nil> update,
causing nil panic later.
- install cds balancer by importing package cdsbalancer
- `net.SplitHostPort` fails when target doesn't have port, but we want to use the original string instead
This PR also adds a new testutils directory with a fake client and a
channel which supports a timed receive operation. In follow up PRs, we
can move other common test stuff like the fake server etc to this
directory and cleanup more tests.
The client will look only at the last route in the list (the default
route), whose match field must contain a prefix field whose value is the
empty string and whose route field must be set.
Continuing the war on stacks, we can reduce the amount of stack required
per-RPC by combining defers from different components into one.
Each defer statement in process{Unary,Streaming}RPC goes on the stack
and occupies about 56-64 bytes the entire lifetime of an RPC, which
could be very long. More importantly, a call to runtime.morestack is
often required to allocate a new, larger stack when the handler
goroutine runs out of stack memory (Go's default stack size is 2 KiB).
Before:
$ go tool objdump <binary> | grep "TEXT.*processUnaryRPC(SB)" -A 10 | grep "SUBQ.*SP"
server.go:867 0x9132fb 4881ec80030000 SUBQ $0x380, SP
$ go tool objdump <binary> | grep "TEXT.*processStreamingRPC(SB)" -A 10 | grep "SUBQ.*SP"
server.go:1099 0x9151bb 4881ec68020000 SUBQ $0x268, SP
After:
$ go tool objdump <binary> | grep "TEXT.*processUnaryRPC(SB)" -A 10 | grep "SUBQ.*SP"
server.go:867 0x9132fb 4881ecd0020000 SUBQ $0x2d0, SP
$ go tool objdump <binary> | grep "TEXT.*processStreamingRPC(SB)" -A 10 | grep "SUBQ.*SP"
server.go:1116 0x9150fb 4881ecf8010000 SUBQ $0x1f8, SP
As one can observe, the processUnaryRPC's stack goes down from 0x380
bytes to 0x2d0 bytes (896 - 720 = 176 bytes) while processStreamingRPC's
stack goes down from 0x2d8 bytes to 0x1f8 bytes (616 - 504 = 112 bytes).
There are probably other things we can do here, but these are some low
hanging fruits to pick off.
This PR removes the xds_client implementation from eds balancer, and replaces it with a xds_client wrapper. (The xds_client wrapper has very similar API as the old xds_client implementation, so the change in the eds balancer is minimal).
The eds balancer currently doesn't look for xds_client from attributes, and always creates a new xds_client. The attributes change will be done in a following up change.
* Add a helper to the fakexds package to return a ClientConn talking to
the fake server.
* Tests will make use of this ClientConn wherever required, or they will
directly pass the fake server's address as the balancerName to the
xdsclient.New() function, thus exercising that code path as well.
* Add grpc.WithTimeout to list in vet.sh
The xds client will parse the EDS response, and give the parse result to eds balancer, so the balancer doesn't need to deal with proto directly.
Also moved `ClusterLoadAssignmentBuilder` to another pacakge to be shared by tests in different packages.
