临时有更改presto端口的需求，配置文件config.properties，

配置文件所在路径：/home/bigdata/local/presto/presto-data/etc

coordinator=true

node-scheduler.include-coordinator=false

http-server.http.port=8091

query.max-memory=96GB

query.max-memory-per-node=16GB

discovery-server.enabled=true

discovery.uri=http://hostname:8091

#hostname:presto主节点

简单将8091替换为8095端口，用salt下发到所有的presto节点，然后出现presto服务不可用的情况。

1.查看presto的worker节点，日志中出现：

2017-12-05T18:12:35.394+0800 DEBUG Query-20171205_101235_00029_9p57n-243 com.facebook.presto.execution.QueryStateMachine Query 20171205_101235_00029_9p57n failed

com.facebook.presto.spi.PrestoException: No worker nodes available

at com.facebook.presto.util.Failures.checkCondition(Failures.java:87)

at com.facebook.presto.sql.planner.SystemPartitioningHandle.getNodePartitionMap(SystemPartitioningHandle.java:149)

at com.facebook.presto.sql.planner.NodePartitioningManager.getNodePartitioningMap(NodePartitioningManager.java:105)

at com.facebook.presto.execution.scheduler.SqlQueryScheduler.lambda$null$0(SqlQueryScheduler.java:140)

at java.util.HashMap.computeIfAbsent(HashMap.java:1126)

at com.facebook.presto.execution.scheduler.SqlQueryScheduler.lambda$new$1(SqlQueryScheduler.java:140)

at com.facebook.presto.execution.scheduler.SqlQueryScheduler.createStages(SqlQueryScheduler.java:241)

at com.facebook.presto.execution.scheduler.SqlQueryScheduler.<init>(SqlQueryScheduler.java:131)

at com.facebook.presto.execution.SqlQueryExecution.planDistribution(SqlQueryExecution.java:434)

at com.facebook.presto.execution.SqlQueryExecution.start(SqlQueryExecution.java:274)

at com.facebook.presto.execution.QueuedExecution.lambda$start$1(QueuedExecution.java:62)

at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)

at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)

at java.lang.Thread.run(Thread.java:745)

和

2017-12-05T18:31:37.551+0800 WARN http-worker-240 com.facebook.presto.execution.SqlTaskManager Switching coordinator affinity from x4cpe to tendi

2017-12-05T18:31:37.613+0800 WARN http-worker-239 com.facebook.presto.execution.SqlTaskManager Switching coordinator affinity from tendi to qgh2a

2017-12-05T18:31:37.764+0800 WARN http-worker-240 com.facebook.presto.execution.SqlTaskManager Switching coordinator affinity from qgh2a to mfu69

原因：worker节点配置文件错误，错把coordinator设置为true。这样就启动了多个master节点，导致master不断切换。

主节点的配置coordinator=true

worker节点的配置coordinator=false

重新替换后presto工作正常。

2.启动的worker节点数少于预期，部分work节点仍然无法启动。

日志中出现：

Caused by: java.net.BindException: Address already in use

常见错误，端口被其他应用占用。

使用lsof -i:8095 查看到tomcat在使用该接口（需切换到root用户下 ）。