Today when we load the Netty plugins, we indirectly cause several Netty
classes to initialize. This is because we attempt to load some classes
by name, and loading these classes is done in a way that triggers a long
chain of class initializers within Netty. We should not do this, this
can lead to log messages before the logger is loader, and it leads to
initialization in cases when the classes would never be needed (for
example, Netty 3 class initialization is never needed if Netty 4 is
used, and vice versa). This commit avoids this early initialization of
these classes by removing the need for the early loading.
Relates #19819
When closing a transport client that depends on Netty 4, interrupted
exceptions can be thrown while shutting down some Netty threads. This
commit refactors the handling of these exceptions to finish shutting
down and then just restore the interrupted status.
Today if the PreBuiltTransportClient is using Netty 4 transport, on
shutdown some Netty 4 threads could linger. This commit causes the
client to wait for these threads to shutdown upon termination.
This change does three things:
1. Makes PreBuiltTransportClientTests run since it was silently
failing on a missing dependency
2. Makes PreBuiltTransportClientTests pass
3. Removes the http.type and transport.type from being set in the
transport clients additional settings since these are set to `netty4` by
default anyway.
The `client/transport` project adds a new jar build project that
pulls in all dependencies and configures all required modules.
Preinstalled modules are:
* transport-netty
* lang-mustache
* reindex
* percolator
The `TransportClient` classes are still in core
while `TransportClient.Builder` has only a protected construcutor
such that users are redirected to use the new `TransportClientBuilder`
from the new jar.
Closes#19412
Jason Tedor
Colin Goodheart-Smithe
Ryan Ernst
Simon Willnauer