`PageCacheRecycler` is the class that creates and holds pages of arrays
for various uses. `BigArrays` is just one user of these pages. This
commit moves the constants that define the page sizes for the recycler
to be on the recycler class.
This is related to #27260. In Elasticsearch all of the messages that we
serialize to write to the network are composed of heap bytes. When you
read or write to a nio socket in java, the heap memory you passed down
must be copied to/from direct memory. The JVM internally does some
buffering of the direct memory, however it is essentially unbounded.
This commit introduces a simple mechanism of buffering and copying the
memory in transport-nio. Each network event loop is given a 64kb
DirectByteBuffer. When we go to read we use this buffer and copy the
data after the read. Additionally, when we go to write, we copy the data
to the direct memory before calling write. 64KB is chosen as this is the
default receive buffer size we use for transport-netty4
(NETTY_RECEIVE_PREDICTOR_SIZE).
Since we only have one buffer per thread, we could afford larger.
However, if we the buffer is large and not all of the data is flushed in
a write call, we will do excess copies. This is something we can
explore in the future.
This commit is related to #32517. It allows an "sni_server_name"
attribute on a DiscoveryNode to be propagated to the server using
the TLS SNI extentsion. Prior to this commit, this functionality
was only support for the netty transport. This commit adds this
functionality to the security nio transport.
This change cleans up "unused variable" warnings. There are several cases were we
most likely want to suppress the warnings (especially in the client documentation test
where the snippets contain many unused variables). In a lot of cases the unused
variables can just be deleted though.
This is related to #27260. It adds the SecurityNioTransport to the
security plugin. Additionally, it adds support for ip filtering. And it
randomly uses the nio transport in security integration tests.
Currently we set local addresses on the creation time of a NioChannel.
However, this may return null as the local address may not have been
set yet. An example is the local address has not been set on a client
channel as the connection process is not yet complete.
This PR modifies the getter to set the local field if it is currently null.
Currently, when we open a new channel, we pass it an
InboundChannelBuffer. The channel buffer is preallocated a single 16kb
page. However, there is no guarantee that this channel will be read from
anytime soon. Instead, this commit does not preallocate that page. That
page will be allocated when we receive a read event.
This is related to #28898. This PR implements pooling of bytes arrays
when reading from the wire in the http server transport. In order to do
this, we must integrate with netty reference counting. That manner in
which this PR implements this is making Pages in InboundChannelBuffer
reference counted. When we accessing the underlying page to pass to
netty, we retain the page. When netty releases its bytebuf, it releases
the underlying pages we have passed to it.
This is related to #27260. Currently when we queue a write with a
channel we set OP_WRITE and wait until the next selection loop to flush
the write. However, if the channel does not have a pending write, it
is probably ready to flush. This PR implements an optimistic flush logic
that will attempt this flush.