Today we ship with default jvm.options for server Elasticsearch that
prevents Netty from using some unsafe optimizations. Yet, the settings
do nothing for the transport client since it is embedded in other
applications that will not read and use those settings. This commit adds
these settings for the transport client, and is done so in a way that
still enables users to go unsafe if they want to go unsafe (they
shouldn't, but the option is there).
Relates #22284
Today there is no way to get notified if a node is disconnected. Client code
must poll the TransportClient constantly to detect that a node is not connected
anymore in order to react and add new nodes or notify altering etc. For instance
if a hostname gets resolved to an IP but that host is disconnected clients want
to reconnect by resolving the hostname again which is a common situation in cloud
environments.
Closes#21424
We kept `netty_3` as a fallback in the 5.x series but now that master
is 6.0 we don't need this or in other words all issues coming up with
netty 4 will be blockers for 6.0.
This commit adds an assumption to
PreBuiltTransportClientTests#testPluginInstalled on JDK 9. The
underlying issue is that Netty attempts to access sun.nio.ch but this
package is not exported from java.base on JDK 9. This throws an uncaught
InaccessibleObjectException causing the test to fail. This assumption
can be removed when Netty 4.1.6 is released as it will include a fix for
this scenario.
Relates #20251
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
Simon Willnauer
Colin Goodheart-Smithe