Add a blog to introduce methods to specify name server for brokers, producers, consumers and mq admin tools.
Project: http://git-wip-us.apache.org/repos/asf/incubator-rocketmq-site/repo Commit: http://git-wip-us.apache.org/repos/asf/incubator-rocketmq-site/commit/bdd8b466 Tree: http://git-wip-us.apache.org/repos/asf/incubator-rocketmq-site/tree/bdd8b466 Diff: http://git-wip-us.apache.org/repos/asf/incubator-rocketmq-site/diff/bdd8b466 Branch: refs/heads/asf-site Commit: bdd8b466f31c8d703400f529ffa432fa307a9f9c Parents: 0b348ef Author: Zhanhui Li <lizhan...@apache.org> Authored: Fri Feb 10 12:09:17 2017 +0800 Committer: Zhanhui Li <lizhan...@apache.org> Committed: Fri Feb 10 12:09:17 2017 +0800 ---------------------------------------------------------------------- ...-methods-to-feed-name-server-address-list.md | 71 ++++++++++++++++++++ 1 file changed, 71 insertions(+) ---------------------------------------------------------------------- http://git-wip-us.apache.org/repos/asf/incubator-rocketmq-site/blob/bdd8b466/_posts/2017-02-10-four-methods-to-feed-name-server-address-list.md ---------------------------------------------------------------------- diff --git a/_posts/2017-02-10-four-methods-to-feed-name-server-address-list.md b/_posts/2017-02-10-four-methods-to-feed-name-server-address-list.md new file mode 100644 index 0000000..f4c78b1 --- /dev/null +++ b/_posts/2017-02-10-four-methods-to-feed-name-server-address-list.md @@ -0,0 +1,71 @@ +--- +title: "Four Methods to Feed Name Server Address List" +categories: + - RocketMQ +tags: + - RocketMQ + - Name Server +--- + +Apache RocketMQ is a distributed system that each components should be properly coordinated to work smoothly. Name +servers are designed to take much of this responsibility through managing topic route information. + +The management, roughly speaking, consists two parts. The first one is that brokers report to name servers on meta data +of themselves and topics they have. The second is serving clients, including producer, consumer and command line + executables these meta data. + +As a result, before launching brokers and clients, we need to feed name server address list to them. Apache RocketMQ +provides four methods to achieve this goal. + +1. Programmatic Way + + For broker, we may specify `namesrvAddr=name-server-ip1:port;name-server-ip2:port` in broker configuration file. + Alternatively, we may pass a parameter like `-n name-server-ip1:port;name-server-ip2:port` to `mqbroker` script. + + For producers and consumers, we may feed name server address list to them as follows: + + ` + DefaultMQProducer producer = new DefaultMQProducer("please_rename_unique_group_name"); + producer.setNamesrvAddr("name-server1-ip:port;name-server2-ip:port");` + + ` + DefaultMQPushConsumer consumer = new DefaultMQPushConsumer("please_rename_unique_group_name"); + consumer.setNamesrvAddr("name-server1-ip:port;name-server2-ip:port");` + + If you use admin command line from shell, you may specify this way: + `sh mqadmin command-name -n name-server-ip1:port;name-server-ip2:port -x other-options` + + a simple example is: + `sh mqadmin -n localhost:9876 clusterList` + assuming to query cluster info on the name server node. + + If integrating admin tool into your own dashboard, you may + `DefaultMQAdminExt defaultMQAdminExt = new DefaultMQAdminExt("please_rename_unique_group_name"); + defaultMQAdminExt.setNamesrvAddr("name-server1-ip:port;name-server2-ip:port");` + + +2. Environment Variable + + You can export `NAMESRV_ADDR` environment variable. Brokers and clients will examine and use its value if set. + + +3. Java Options + + Similar to environment variable, you may specify the sequel java option `rocketmq.namesrv.addr` before launching your + application. + +4. HTTP endpoint + + If you do not specify name server address list using previously mentioned methods, Apache RocketMQ will periodically + access the following HTTP end point to acquire and update name server address list. + + On default, the end point is: + + `http://jmenv.tbsite.net:8080/rocketmq/nsaddr` + + You may override `jmenv.tbsite.net` by this java option: `rocketmq.namesrv.domain`, + You may also override `nsaddr` part by this java option: `rocketmq.namesrv.domain.subgroup` + + This method is recommended because it gives you maximum flexibility, aka, you can dynamically add or + remove name server node without necessity of rebooting your brokers and clients according to your name servers' + system load. \ No newline at end of file
