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From jkr...@apache.org
Subject svn commit: r1575029 - /kafka/site/081/design.html
Date Thu, 06 Mar 2014 20:23:06 GMT
Author: jkreps
Date: Thu Mar  6 20:23:06 2014
New Revision: 1575029

URL: http://svn.apache.org/r1575029
Fix image alignment.


Modified: kafka/site/081/design.html
URL: http://svn.apache.org/viewvc/kafka/site/081/design.html?rev=1575029&r1=1575028&r2=1575029&view=diff
--- kafka/site/081/design.html (original)
+++ kafka/site/081/design.html Thu Mar  6 20:23:06 2014
@@ -258,6 +258,7 @@ This functionality is inspired by one of
 <h4>Log Compaction Basics</h4>
 Here is a high-level picture that shows the logical structure of a Kafka log with the offset
for each message.
 <img src="/images/log_cleaner_anatomy.png">
 The head of the log is identical to a traditional Kafka log. It has dense, sequential offsets
and retains all messages. Log compaction adds an option for handling the tail of the log.
The picture above shows a log with a compacted tail. Note that the messages in the tail of
the log retain the original offset assigned when they were first written&mdash;that never
changes. Note also that all offsets remain valid positions in the log, even if the message
with that offset has been compacted away; in this case this position is indistinguishable
from the next highest offset that does appear in the log. For example, in the picture above
the offsets 36, 37, and 38 are all equivalent positions and a read beginning at any of these
offsets would return a message set beginning with 38.

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