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new fb66b3668b KAFKA-13799: Improve documentation for Kafka zero-copy
(#12052)
fb66b3668b is described below
commit fb66b3668bd0a257a77ca43f7b1a31e8180f21f8
Author: RivenSun <[email protected]>
AuthorDate: Thu Apr 21 01:31:32 2022 +0800
KAFKA-13799: Improve documentation for Kafka zero-copy (#12052)
Improve documentation for Kafka zero-copy. Kafka combines pagecache and
zero-copy to greatly improve message consumption efficiency. But zero-copy only
works in PlaintextTransportLayer.
Reviewers: Divij Vaidya <[email protected]>, Guozhang Wang
<[email protected]>
---
docs/design.html | 3 +++
1 file changed, 3 insertions(+)
diff --git a/docs/design.html b/docs/design.html
index db71b65245..15eefa8132 100644
--- a/docs/design.html
+++ b/docs/design.html
@@ -125,6 +125,9 @@
<p>
This combination of pagecache and sendfile means that on a Kafka cluster
where the consumers are mostly caught up you will see no read activity on the
disks whatsoever as they will be serving data entirely from cache.
<p>
+ TLS/SSL libraries operate at the user space (in-kernel
<code>SSL_sendfile</code> is currently not supported by Kafka). Due to this
restriction, <code>sendfile</code> could not be used when transport layer
enables SSL protocol. For enabling
+ SSL configuration, refer to <code>security.protocol</code> and
<code>security.inter.broker.protocol</code>
+ <p>
For more background on the sendfile and zero-copy support in Java, see
this <a href="https://developer.ibm.com/articles/j-zerocopy/">article</a>.
<h4 class="anchor-heading"><a id="design_compression"
class="anchor-link"></a><a href="#design_compression">End-to-end Batch
Compression</a></h4>