不爲也 比不能也

Elasticsearch provides failover capabilities by keeping multiple copies of your data in the cluster. In presence of network disruptions or failing nodes, changes might not make it to all the copies. This blog post showcases one of the internal mechanics of Elasticsearch to identify shard copies that are missing changes, providing an in-depth view on how two central components, the consensus modu..

Beep… beep… beep… It’s PagerDuty telling you that a node has gone down, or a rack has gone down, or your whole cluster has just rebooted. Either way, your cluster is RED: some shards are not assigned, which means that your data is not fully available.bepp... bepp... bepp... 호출기가 울린다. node 혹은 rack에 장애가 발생했다. 또는 전체 cluster가 reboot 되었다. 어느 쪽이든 cluster가 RED(일부 shard가 할당되지 않았다. 즉, data를 완전히 사용할 수 없다...

Queries can become quite complex and, especially when combined with different analyzers and field mappings, can become a bit difficult to follow. The validate-query API can be used to check whether a query is valid.query는 꽤 복잡해질 수 있고, 특히 다른 analyzer와 field mapping이 조합되었을 경우, 따라 가기가 약간 어려워질 수 있다. validate-query API는 query가 유효한가를 확인하는데 사용된다.GET /gb/tweet/_validate/query { "query": { "tweet" : { "m..

We’ve mentioned that, by default, results are returned in descending order of relevance. But what is relevance? How is it calculated?기본적으로 결과는 relevance를 기준으로, 내림차순으로 반환된다고 언급한 바 있다. 그런데, relevance가 무엇이고, 어떻게 계산되는가?The relevance score of each document is represented by a positive floating-point number called the _score. The higher the _score, the more relevant the document.각 document의 relevance ..

Queries can find only terms that actually exist in the inverted index, so it is important to ensure that the same analysis process is applied both to the document at index time, and to the query string at search time so that the terms in the query match the terms in the inverted index.query는 inverted index에 실제로 존재하는 단어만을 찾을 수 있다. 따라서 document를 index할할 때 적용되는 프로세스와, 검색 시 query string에 적용되는 프로세스가,..