15、SolrCloud 集群使用手册之 Collections API
1.创建collection
name：指明collection名字
router.name：指定路由策略，默认为compositeId路由
numShards：collection的逻辑分片数量
shards：指定具体的shard列表
replicationFactor：一个分片的replicas数量
maxShardsPerNode ：一个solr节点上可以创建的逻辑分片数量，默认值为1
createNodeSet：可以指定在那些solr节点上创建collection
路由规则
SolrCloud中对于文档分布在哪个shard上，提供了两种路由算法：compositeId和implicit
在创建Collection时，需要通过router.name指定路由策略，默认为compositeId路由。
compositeId#
该路由为一致性哈希路由，shards的哈希范围从80000000~7fffffff。初始创建collection是必须指定numShards个数，compositeId路由算法根据numShards的个数，计算出每个shard的哈希范围，因此路由策略不可以扩展shard。
implicit#
该路由方式指定索引具体落在路由到哪个Shard，这与compositeId路由方式索引可均匀分布在每个shard上不同。同时只有在implicit路由策略下才可创建shard。
利用solrJ新建索引时，需要在代码中指定索引具体落在哪个shard上，添加代码：
doc.addField("_route_", "shard_X");
同时在schema.xml添加字段
当我们想指定配置文件，索引目录时，可以加入如下参数
| property.name=value |
string |
No |
Set core property name to value. See core.properties file contents. |
可选参数如下：
| key |
Description |
| name |
The name of the SolrCore. You'll use this name to reference the SolrCore when running commands with the CoreAdminHandler. |
| config |
The configuration file name for a given core. The default is solrconfig.xml. |
| schema |
The schema file name for a given core. The default is schema.xml |
| dataDir |
Core's data directory as a path relative to the instanceDir, data by default. |
| configSet |
If set, the name of the configset to use to configure the core (see Config Sets). |
| properties |
The name of the properties file for this core. The value can be an absolute pathname or a path relative to the value of instanceDir. |
| transient |
If true, the core can be unloaded if Solr reaches the transientCacheSize. The default if not specified is false. Cores are unloaded in order of least recently used first. |
| loadOnStartup |
If true, the default if it is not specified, the core will loaded when Solr starts. |
| coreNodeName |
Added in Solr 4.2, this attributes allows naming a core. The name can then be used later if you need to replace a machine with a new one. By assigning the new machine the same coreNodeName as the old core, it will take over for the old SolrCore. |
| ulogDir |
The absolute or relative directory for the update log for this core (SolrCloud) |
| shard |
The shard to assign this core to (SolrCloud) |
| collection |
The name of the collection this core is part of (SolrCloud) |
| roles |
Future param for SolrCloud or a way for users to mark nodes for their own use. |
使用Collections API：CREATE来创建collection时需要符合下面的条件。
shards*replicationFactor <= maxShardsPerNode*Node数
http://192.168.137.171:8080/solr-cloud/admin/collections?action=CREATE&name=myc&numShards=2&replicationFactor=3&maxShardsPerNode=2
http://192.168.137.171:8080/solr-cloud/admin/collections?action=CREATE&name=myc2&numShards=2&replicationFactor=2&maxShardsPerNode=2&createNodeSet=192.168.137.171:8080_solr-cloud,192.168.137.172:8080_solr-cloud
http://192.168.137.171:8080/solr-cloud/admin/collections?action=CREATE&name=myc3&router.name=implicit&shards=shard1,shard2&replicationFactor=3&maxShardsPerNode=3
指定配置文件
http://192.168.137.171:8080/solr-cloud/admin/collections?action=CREATE&name=myc2&numShards=2&replicationFactor=3&maxShardsPerNode=2&collection.configName=myconf2&property.config=solrconfig2.xml&property.schema=schema2.xml
2.删除collection
http://192.168.137.171:8080/solr-cloud/admin/collections?action=DELETE&name=myc2
3.RELOAD collection
如果schema中的属性有变动，只需要将正确的schema上传到服务器上之后重启solr即可
http://192.168.137.171:8080/solr-cloud/admin/collections?action=RELOAD&name=myc
4. SPLITSHARD(纵向扩容)
使用Collections API：SPLITSHARD来创建SHARD时不需要符合下面的条件。
shards*replicationFactor <= maxShardsPerNode*Node数
整体逻辑：无缝连接和无downtime
旧shard此时继续提供服务并把旧索引转到新的shard上
旧shard同时继续索引新文档
旧shard同时把新文档转发给新shard，新shard索引新文档
旧索引全部迁移到新shard之后，旧shard关闭，新文档直接转发到新的shard上了
手动利用DELETESHARD API删除旧shard
implicit路由：只要创建Shard即可: 新建索引时，将索引建到新建Shard上，查询操作时，指定collection名称，得到的仍是整个集群返回的结果。
compositeId路由：通过分裂（SPLITSHARD）操作实现。
http://192.168.137.171:8080/solr-cloud/admin/collections?action=SPLITSHARD&collection=myc&shard=shard1
5.CREATESHARD
路由规则为implicit 时才可以使用。
使用Collections API：CREATESHARD来创建shard时需要符合下面的条件。
shards*replicationFactor <= maxShardsPerNode*Node数
http://192.168.137.171:8080/solr-cloud/admin/collections?action=CREATESHARD&collection=myc3&shard=shard3
6. DELETESHARD
删除inactive shard
http://192.168.137.171:8080/solr-cloud/admin/collections?action=DELETESHARD&collection=myc2&shard=shard1
7.CREATEALIAS
实现跨collection查询，新建和修改都是使用CREATEALIAS。
http://192.168.137.171:8080/solr-cloud/admin/collections?action=CREATEALIAS&name=newc&collections=myc,myc2
8.DELETEALIAS
http://192.168.137.171:8080/solr-cloud/admin/collections?action=DELETEALIAS&name=newc
]
9.DELETEREPLICA
http://192.168.137.171:8080/solr-cloud/admin/collections?action=DELETEREPLICA&collection=myc2&shard=shard2&replica=192.168.137.171:8080_solr-cloud_myc2_shard2_replica2
10.ADDREPLICA
http://192.168.137.171:8080/solr-cloud/admin/collections?action=ADDREPLICA&collection=myc2&shard=shard2&node=192.168.137.171:8080_solr-cloud
使用Collections API：ADDREPLICA来创建replica时不需要符合下面的条件。
shards*replicationFactor <= maxShardsPerNode*Node数