搭建 SolrCloud
以 cloud 模式启动
登录到 sc78，以 cloud 模式启动 solr
[root@sc78 ~]# /data/solr/bin/solr start -cloud -z zk:2181/sc
Waiting up to 30 seconds to see Solr running on port 8983 [/]
Started Solr server on port 8983 (pid=1871). Happy searching!
说明
-cloud表示以cloud模式启动solr-z zk:2181/sc表示ZooKeeper连接串为zk:2181/sc，即以zk上的/sc作为SolrCloud配置的根节点
那么 SolrCluoud 启动成功了吗？执行 status 命令查看一下
[root@sc78 ~]# /data/solr/bin/solr status
Found 1 Solr nodes:
Solr process 1871 running on port 8983
ERROR: Failed to get system information from http://localhost:8983/solr due to: org.apache.http.client.ClientProtocolException: Expected JSON response from server but received: <html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8"/>
<title>Error 404 Not Found</title>
</head>
<body><h2>HTTP ERROR 404</h2>
<p>Problem accessing /solr/admin/info/system. Reason:
<pre> Not Found</pre></p><hr><i><small>Powered by Jetty://</small></i><hr/>
</body>
</html>
Typically, this indicates a problem with the Solr server; check the Solr server logs for more information.
看来 Solr 确实启动了，但是无法获取系统信息。经过检查，发现这是因为 ZooKeeper 上木有 /sc 这个节点的原因，连接到 zk 上运行 zkCli.sh 脚本，执行 ls 命令，如下
[zk: localhost:2181(CONNECTED) 0] ls /
[zookeeper]
可见，当前 zk 上仅有一个节点：/zookeeper。所以要先在 zk 上创建 /sc 节点
[zk: localhost:2181(CONNECTED) 1] create /sc null
Created /sc
然后在 sc78 上重新启动 SolrCloud
停止 solr 进程
[root@sc78 ~]# /data/solr/bin/solr stop
Sending stop command to Solr running on port 8983 ... waiting 5 seconds to allow Jetty process 1871 to stop gracefully.
以 cloud 模式启动 solr
[root@sc78 ~]# /data/solr/bin/solr start -cloud -z zk:2181/sc
Waiting up to 30 seconds to see Solr running on port 8983 [/]
Started Solr server on port 8983 (pid=2240). Happy searching!
查看 solr 状态
[root@sc78 ~]# /data/solr/bin/solr status
Found 1 Solr nodes:
Solr process 2240 running on port 8983
{
"solr_home":"/data/solr/server/solr",
"version":"5.5.2 8e5d40b22a3968df065dfc078ef81cbb031f0e4a - sarowe - 2016-06-21 11:44:11",
"startTime":"2016-08-22T06:45:44.443Z",
"uptime":"0 days, 0 hours, 0 minutes, 11 seconds",
"memory":"68.2 MB (%13.9) of 490.7 MB",
"cloud":{
"ZooKeeper":"zk:2181/sc",
"liveNodes":"1",
"collections":"0"}}
通过浏览器访问 solr 管理页面 http://sc78:8983/solr/#/
可以看到 SolrCloud 已经成功启动，点击左侧菜单栏的 Cloud-Tree
显示的实际上是 ZooKeeper 的 /sc 节点信息，其中 /live_nodes 节点下有一个名为 172.17.21.78:8983_solr 的节点，这表示 SolrCloud 集群当前有一个节点，该节点是运行在 172.17.21.78 上，监听端口为 8983 的 solr 实例。
我们连接到 zk 上看下是否如此
[zk: localhost:2181(CONNECTED) 0] ls /
[sc, zookeeper]
[zk: localhost:2181(CONNECTED) 1] ls /sc
[security.json, clusterstate.json, aliases.json, live_nodes, overseer, overseer_elect, collections]
[zk: localhost:2181(CONNECTED) 2] ls /sc/live_nodes
[172.17.21.78:8983_solr]