Question

我正在运行一个docker-swarm管理器节点（18.09.6），并且正在玩cassandra集群。我正在使用以下定义，它的工作方式是种子/主节点和从属节点向上旋转，并可以通信/复制其数据/模式，这些更改很好：

services:
  cassandra-masters:
    image: cassandra:2.2
    environment:
      - MAX_HEAP_SIZE=128m
      - HEAP_NEWSIZE=32m
      - CASSANDRA_BROADCAST_ADDRESS=cassandra-masters
    deploy:
      mode: replicated
      replicas: 1
  cassandra-slaves:
    image: cassandra:2.2
    environment:
      - MAX_HEAP_SIZE=128m
      - HEAP_NEWSIZE=32m
      - CASSANDRA_SEEDS=cassandra-masters
      - CASSANDRA_BROADCAST_ADDRESS=cassandra-slaves
    deploy:
      mode: replicated
      replicas: 1
    depends_on:
      - cassandra-masters

当我将副本数从1更改为2时，无论是在堆栈部署还是在后期部署规模上，都将创建cassandra从属的第二个任务，但始终失败，并显示错误消息，表明它无法与种子节点闲聊：

INFO  10:51:03 Loading persisted ring state
INFO  10:51:03 Starting Messaging Service on /10.10.0.200:7000 (eth0
INFO  10:51:03 Handshaking version with cassandra-masters/10.10.0.142
Exception (java.lang.RuntimeException) encountered during startup: Unable to gossip with any seeds
java.lang.RuntimeException: Unable to gossip with any seeds
    at org.apache.cassandra.gms.Gossiper.doShadowRound(Gossiper.java:1360)
    at org.apache.cassandra.service.StorageService.checkForEndpointCollision(StorageService.java:521)
    at org.apache.cassandra.service.StorageService.prepareToJoin(StorageService.java:756)
    at org.apache.cassandra.service.StorageService.initServer(StorageService.java:676)
    at org.apache.cassandra.service.StorageService.initServer(StorageService.java:562)
    at org.apache.cassandra.service.CassandraDaemon.setup(CassandraDaemon.java:310)
    at org.apache.cassandra.service.CassandraDaemon.activate(CassandraDaemon.java:548)
    at org.apache.cassandra.service.CassandraDaemon.main(CassandraDaemon.java:657)
ERROR 10:51:34 Exception encountered during startup
java.lang.RuntimeException: Unable to gossip with any seeds
    at org.apache.cassandra.gms.Gossiper.doShadowRound(Gossiper.java:1360) ~[apache-cassandra-2.2.14.jar:2.2.14]
    at org.apache.cassandra.service.StorageService.checkForEndpointCollision(StorageService.java:521) ~[apache-cassandra-2.2.14.jar:2.2.14]
    at org.apache.cassandra.service.StorageService.prepareToJoin(StorageService.java:756) ~[apache-cassandra-2.2.14.jar:2.2.14]
    at org.apache.cassandra.service.StorageService.initServer(StorageService.java:676) ~[apache-cassandra-2.2.14.jar:2.2.14]
    at org.apache.cassandra.service.StorageService.initServer(StorageService.java:562) ~[apache-cassandra-2.2.14.jar:2.2.14]
    at org.apache.cassandra.service.CassandraDaemon.setup(CassandraDaemon.java:310) [apache-cassandra-2.2.14.jar:2.2.14]
    at org.apache.cassandra.service.CassandraDaemon.activate(CassandraDaemon.java:548) [apache-cassandra-2.2.14.jar:2.2.14]
    at org.apache.cassandra.service.CassandraDaemon.main(CassandraDaemon.java:657) [apache-cassandra-2.2.14.jar:2.2.14]

我想了解导致问题的原因以及是否有解决方法？我只是在调查要进入生产阶段的任何障碍，我们显然会在不同的节点而不是一个节点上旋转cassandra任务/副本。

编辑：我将相同的堆栈旋转到两个节点上，并且看到的是相同的行为，即，当我扩展到第二个“从属”任务时，它将失败相同的错误，因此在同一节点上尝试运行两个任务并不是一个特别的问题。

Answer 1

我还没有弄清楚八卦失败的原因，但最终我们达成了生产部署策略，在该策略中，我们不需要自动扩展，而应该根据系统的行为和预期流量进行容量规划。这个答案还指出了自动缩放可能给已经拉伸的系统带来的额外压力：AWS and auto scaling cassandra

单个docker-swarm节点上的Cassandra副本

1 个答案: