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Posted to commits@pulsar.apache.org by ur...@apache.org on 2022/05/25 18:05:55 UTC
[pulsar-site] branch main updated: Docs sync done from apache/pulsar(#e2b264b)
This is an automated email from the ASF dual-hosted git repository.
urfree pushed a commit to branch main
in repository https://gitbox.apache.org/repos/asf/pulsar-site.git
The following commit(s) were added to refs/heads/main by this push:
new 4472fb14a89 Docs sync done from apache/pulsar(#e2b264b)
4472fb14a89 is described below
commit 4472fb14a89d93d5e4cb5b36a16565f1c4f65a70
Author: Pulsar Site Updater <de...@pulsar.apache.org>
AuthorDate: Wed May 25 18:05:50 2022 +0000
Docs sync done from apache/pulsar(#e2b264b)
---
site2/website-next/docs/concepts-messaging.md | 8 +++++---
1 file changed, 5 insertions(+), 3 deletions(-)
diff --git a/site2/website-next/docs/concepts-messaging.md b/site2/website-next/docs/concepts-messaging.md
index b3520d70e8b..484099fc8f1 100644
--- a/site2/website-next/docs/concepts-messaging.md
+++ b/site2/website-next/docs/concepts-messaging.md
@@ -545,7 +545,7 @@ When a subscription has no consumers, its subscription type is undefined. The ty
#### Exclusive
-In *Exclusive* type, only a single consumer is allowed to attach to the subscription. If multiple consumers subscribe to a topic using the same subscription, an error occurs.
+In *Exclusive* type, only a single consumer is allowed to attach to the subscription. If multiple consumers subscribe to a topic using the same subscription, an error occurs. Note that if the topic is partitioned, all partitions will be consumed by the single consumer allowed to be connected to the subscription.
In the diagram below, only **Consumer A-0** is allowed to consume messages.
@@ -555,12 +555,14 @@ In the diagram below, only **Consumer A-0** is allowed to consume messages.
#### Failover
-In *Failover* type, multiple consumers can attach to the same subscription. A master consumer is picked for non-partitioned topic or each partition of partitioned topic and receives messages. When the master consumer disconnects, all (non-acknowledged and subsequent) messages are delivered to the next consumer in line.
+In *Failover* type, multiple consumers can attach to the same subscription. A master consumer is picked for non-partitioned topic or for each partition of partitioned topic and receives messages. When the master consumer disconnects, all (non-acknowledged and subsequent) messages are delivered to the next consumer in line.
-For partitioned topics, broker will sort consumers by priority level and lexicographical order of consumer name. Then broker will try to evenly assigns topics to consumers with the highest priority level.
+For partitioned topics, broker will sort consumers by priority level and lexicographical order of consumer name. Then broker will try to evenly assigns partitions to consumers with the highest priority level.
For non-partitioned topic, broker will pick consumer in the order they subscribe to the non partitioned topic.
+For example: a partitioned topic has 15 partitions, and 3 consumers. Each consumer will be active for 5 partitions. Each partition will have 1 active consumer and 4 stand-by consumers.
+
In the diagram below, **Consumer-B-0** is the master consumer while **Consumer-B-1** would be the next consumer in line to receive messages if **Consumer-B-0** is disconnected.
