From 3661768969c3d31f1d9cbdd64bcd4714187bf2d2 Mon Sep 17 00:00:00 2001 From: Weny Xu Date: Mon, 15 Jul 2024 19:40:04 +0800 Subject: [PATCH] chore: apply suggestions from CR --- docs/nightly/en/user-guide/operations/region-failover.md | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/docs/nightly/en/user-guide/operations/region-failover.md b/docs/nightly/en/user-guide/operations/region-failover.md index 7adf5e3d5..6a071d908 100644 --- a/docs/nightly/en/user-guide/operations/region-failover.md +++ b/docs/nightly/en/user-guide/operations/region-failover.md @@ -1,6 +1,6 @@ # Region Failover -Region Failover provides the ability to recover regions from crashed Datanodes without losing data. This is implemented via [Region Migration](/user-guide/operations/region-migration). +Region Failover provides the ability to recover regions from region failures without losing data. This is implemented via [Region Migration](/user-guide/operations/region-migration). ## Enable the Region Failover @@ -37,7 +37,7 @@ In best practices, the number of topics/partitions supported by a Kafka cluster ### The read amplification -The data belonging to a specific region consists of data files plus data in the WAL (typically `WAL[LastCheckpoint...Latest]`). The failover of a specific region from a crashed datanode to another datanode only requires reading the WAL data to reconstruct the memory state, which is called region replaying. However, If multiple regions share a single topic, replaying data for a specific region from the topic requires filtering out unrelated data (i.e., data from other regions). **This means replaying data for a specific region from the topic requires reading more data than the actual size of the region's data in the topic, a phenomenon known as read amplification**. +The data belonging to a specific region consists of data files plus data in the WAL (typically `WAL[LastCheckpoint...Latest]`). The failover of a specific region only requires reading the region's WAL data to reconstruct the memory state, which is called region replaying. However, If multiple regions share a single topic, replaying data for a specific region from the topic requires filtering out unrelated data (i.e., data from other regions). **This means replaying data for a specific region from the topic requires reading more data than the actual size of the region's data in the topic, a phenomenon known as read amplification**. Although multiple regions share the same topic, allowing the Datanode to support more regions, the cost of this approach is read amplification during WAL replay.