HealthCheckThread is replaced by StartHealthCheck function in socket.cpp, but some of the docs/comments are not modified correspondingly. There are 3 files that HealthCheckThread is involved in:

• test/brpc_socket_unittest.cpp(3 occurrences)
• docs/cn/load_balancing.md(1 occurrence)
• src/brpc/socket.h(1 occurrence)

All sentences with 'HealthCheckThread' should be rewritten to sync with the

Let's support at least reading "b3" header from a single string, most commonly traceid-spanid-1
It would also be nice to support optionally writing this, especially in message providers or others with constrained environments.

Expected behavior

As discussed on openzipkin/b3-propagation#21 and first implemented here: https://github.com/openzipkin/brave/blob/master/brave/src/main/java/bra

We currently have this code https://github.com/hyperium/tonic/blob/master/tonic/src/status.rs#L344 which maps h2::Error into proper Code's. We should test and ensure that if the user enables the transport feature we can downcast the errors into h2 variants and mapping them to correct status codes.

Currently, the number of threads of a blocking task executor could be configured only by Flags.numCommonBlockingTaskThreads().
If a user who avoid using flags, he or she has to manually copy the factory code.

I think we can add a new builder method to ServerBuilder that takes the number of threads.

public ServerBuilder blockingTaskExecutor(int numThreads) {
    return ...;
}