1、partial update基本语法
POST /index/type/id/_update
{
"doc" : {
"要修改的少数几个field即可,不需要全量的数据"
}
}
每次就传递少数几个发生修改的field即可,不需要将全量的document数据发送过去
2、partial update实现原理以及优点
3、例子:
POST /test_index/test_type/10/_update
{
"doc": {
"test_field2":"update test2"
}
}
4、基于groovy脚本,如何执行partial update
PUT /test_index/test_type/11
{
"num": 0,
"tags": []
}
(1)内置脚本
POST /test_index/test_type/11/_update
{
"script" : "ctx._source.num+=1"
}
{
"_index": "test_index",
"_type": "test_type",
"_id": "11",
"_version": 2,
"found": true,
"_source": {
"num": 1,
"tags": []
}
}
(2)外部脚本
ctx._source.tags+=new_tag
POST /test_index/test_type/11/_update
{
"script": {
"lang": "groovy",
"file": "test-add-tags",
"params": {
"new_tag": "tag1"
}
}
}
(3)用脚本删除文档
ctx.op = ctx._source.num == count ? ‘delete’ : ‘none’
POST /test_index/test_type/11/_update
{
"script": {
"lang": "groovy",
"file": "test-delete-document",
"params": {
"count": 1
}
}
}
(4)upsert操作
POST /test_index/test_type/11/_update
{
"doc": {
"num": 1
}
}
{
"error": {
"root_cause": [
{
"type": "document_missing_exception",
"reason": "[test_type][11]: document missing",
"index_uuid": "6m0G7yx7R1KECWWGnfH1sw",
"shard": "4",
"index": "test_index"
}
],
"type": "document_missing_exception",
"reason": "[test_type][11]: document missing",
"index_uuid": "6m0G7yx7R1KECWWGnfH1sw",
"shard": "4",
"index": "test_index"
},
"status": 404
}
如果指定的document不存在,就执行upsert中的初始化操作;如果指定的document存在,就执行doc或者script指定的partial update操作
POST /test_index/test_type/11/_update
{
"script" : "ctx._source.num+=1",
"upsert": {
"num": 0,
"tags": []
}
}
5、partial update乐观锁并发控制原理
retry策略
POST /index/type/id/_update?retry_on_conflict=5&version=6