This adds the required changes/checks so that the build can run on
FreeBSD.
There are a few things that differ between FreeBSD and Linux:
- CPU probes return -1 for CPU usage
- `hot_threads` cannot be supported on FreeBSD
From OpenJDK's `os_bsd.cpp`:
```c++
bool os::is_thread_cpu_time_supported() {
#ifdef __APPLE__
return true;
#else
return false;
#endif
}
```
So this API now returns (for each FreeBSD node):
```
curl -s localhost:9200/_nodes/hot_threads
::: {Devil Hunter Gabriel}{q8OJnKCcQS6EB9fygU4R4g}{127.0.0.1}{127.0.0.1:9300}
hot_threads is not supported on FreeBSD
```
- multicast fails in native `join` method - known bug:
https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=193246
Which causes:
```
1> Caused by: java.net.SocketException: Invalid argument
1> at java.net.PlainDatagramSocketImpl.join(Native Method)
1> at java.net.AbstractPlainDatagramSocketImpl.join(AbstractPlainDatagramSocketImpl.java:179)
1> at java.net.MulticastSocket.joinGroup(MulticastSocket.java:323)
1> at org.elasticsearch.plugin.discovery.multicast.MulticastChannel$Plain.buildMulticastSocket(MulticastChannel.java:309)
```
So these tests are skipped on FreeBSD.
Resolves#15562
In this commit we increase the queue size of the bulk pool in
BulkProcessorRetryIT to make it less sensitive.
As this test case should stress the pool so bulk processor needs to
back off but not so much that the backoff policy will give up at
some point (which is a valid condition), we still keep it below the
default queue size of 50.
Some tests, but in particular CodecTests, are slow because they test all
versions that ever existed even though they should only test supported
versions.
Today we throttle recoveries only for incoming recoveries. Nodes that have a lot
of primaries can get overloaded due to too many recoveries. To still keep that at bay
we limit the number of threads that are sending files to the target to overcome this problem.
The right solution here is to also throttle the outgoing recoveries that are today unbounded on
the master and don't start the recovery until we have enough resources on both source and target nodes.
The concurrency aspects of the recovery source also added a lot of complexity and additional threadpools
that are hard to configure. This commit removes the concurrent streamns notion completely and sends files
in the thread that drives the recovery simplifying the recovery code considerably.
Outgoing recoveries are not throttled on the master via a allocation decider.
We added this undocumented realtime setting as backup plan long ago
but to date we haven't had a situation where it was a problem. It's reducing
the number of filehandles in the NRT case dramatically and should always be enabled.
Today the logic to async - commit the translog is in every translog instance
itself. While the setting is a per index setting we manageing it per shard. This
polluts the translog code and can more easily be managed in IndexService.
Today we have two variants of translogs for indexing. We only recommend the buffered
one which also has a 20% advantage in indexing speed. This commit removes the option and defaults
to the buffered case. It also hard-wires the translog buffer to 8kb instead of 64kb. We used to
adjust that buffer based on if the shard is active or not, this code has also been removed and
instead we just keep an 8kb buffer arround.