Elasticsearch en producción Monitoreo, problemas y setup recomendado in 15 minutes (or less!) 1 

2 Javier Rey Tryolabs @vierja github.com/vierja [email protected] 

Monitoreo ⌚ Cosas a medir • Estado del cluster Shards Segments Tasks • Estado de nodo Hardware JVM Cache • Uso de aplicaciones Be warned that being an expert is more than understanding how a system is supposed to work. Expertise is gained by investigating why a system doesn’t work. - Brian Redman 3 

Status (duh!) relocating_shards initializing_shards unassigned_shards delayed_unassigned_shards Porcentaje de documentos eliminados Cantidad de segments 50-150 por índice Cantidad de documentos, tamaño Shards y Segments GET /_cluster/health
 {
 "cluster_name": "elasticsearch",
 "status": "yellow",
 "timed_out": false,
 "number_of_nodes": 1,
 "number_of_data_nodes": 1,
 "active_primary_shards": 10,
 "active_shards": 10,
 "relocating_shards": 0,
 "initializing_shards": 0,
 "unassigned_shards": 10,
 "delayed_unassigned_shards": 0,
 "number_of_pending_tasks": 0,
 "number_of_in_flight_fetch": 0,
 "task_max_waiting_in_queue_millis": 0,
 "active_shards_percent_as_number": 50
 } 4 ❗ Tasks Tareas pendientes Hay alguna tarea colgada? 

Hardware CPU load Free space Open file descriptors / Max file descriptors Swap? ☠ 5 JVM Heap usage Garbage collection (count & times, young & old) Cache (filter_cache, fielddata) Cache size Evictions Fielddata circuit breakers Uso de aplicaciones Request rate Query latency Per shard query latency Index rate Delete rate “etc rate” 

Como medirlas Idealmente New Relic Elasticsearch plugin https://github.com/s12v/newrelic-elasticsearch Marvel https://www.elastic.co/products/marvel 6 ”Plugins” (sin instalar) Whatson https://github.com/xyu/elasticsearch-whatson 
 elastichq
 http://www.elastichq.org/app/index.php
 
 kopf
 https://github.com/lmenezes/elasticsearch-kopf
 
 bigdesk
 http://bigdesk.org/
 
 paramedic
 https://github.com/karmi/elasticsearch-paramedic API (BYO) Cat API
 GET /_cat 

GET /_cat/
 =^.^= 
 /_cat/allocation
 /_cat/shards
 /_cat/shards/{index}
 /_cat/master
 /_cat/nodes
 /_cat/indices
 /_cat/indices/{index}
 /_cat/segments
 /_cat/segments/{index}
 /_cat/count
 /_cat/count/{index}
 /_cat/recovery
 /_cat/recovery/{index}
 /_cat/health
 /_cat/pending_tasks
 /_cat/aliases
 /_cat/aliases/{alias}
 /_cat/thread_pool
 /_cat/plugins
 /_cat/fielddata
 /_cat/fielddata/{fields}
 /_cat/nodeattrs
 /_cat/repositories
 /_cat/snapshots/{repository} 7 GET /_cat/segments?v&h=shard,segment,docs.count,size.memory
 shard segment docs.count size.memory
 0 _c 12855 10511
 0 _l 18655 13055
 0 _m 2747 5394
 0 _n 49 3483
 0 _o 319 3460
 0 _p 3364 5851
 0 _q 2148 4743
 1 _m 17124 12742
 1 _v 23005 14209
 2 _c 9987 9236
 2 _l 2992 5565
 2 _m 17604 13041
 2 _n 165 4533
 2 _o 2866 5448
 2 _p 3213 5522
 2 _q 33 3335
 2 _r 556 3702
 2 _s 2408 5003
 3 _l 22082 14204
 3 _v 11427 9837
 3 _w 514 3722
 3 _x 2693 5291
 3 _y 168 4614
 3 _z 2900 5363 

Problemas típicos Nodo Configuración Cluster (mal) Uso 8 

Nodo Swap configurado Heap size mal configurado Memory pressure Mucho garbage collection filter_cache lleno Storage Network storage Lento Mal configurado (max open files) Merge throttling Circuit breakers 9 

Configuración Cantidad de shards Over sharding Mappings mal configurados Mappings for defecto Campos analyzed innecesarios Data path 10 Cluster ☁ Split brain Problemas de bandwidth que afectan replication Multicast (mal) Uso Estructuración SQL → NoSQL Nested objects muy grandes Paginados gigantescos sin _scroll (bots) Muchos updates → muchos deleted → mucho merging → ??? 

Set-up recomendado ✅ Mecanismo de actualización Sin downtime Sin pérdida de datos (o fácil de repopular) Elasticsearch 2.X doc_values por defecto Better query execution planner using filters. Query profiler Optimización de geoqueries Merging optimizations Better recovery 11 RAM > CPU >= 2 core (index es CPU-bound) SSD No más de 32 GB Hardware 

Max 50 GB / shard Non-default mapping Rolling indices (time series data) Master dedicados Nro de réplicas: 1 (si no se agregan más nodos) 12 Configuración y settings importantes bootstrap.mlockall: true
 cluster.name: ‘Nombre del cluster’ 
 discovery.zen.minimum_master_nodes: 2
 refresh_time: >1s ? path:
 data:
 logs:
 plugins: discovery.zen.ping.unicast.hosts: [“host1”, …] 

Preguntas? 13