简介
同Hive Hook一样,Presto也支持自定义实现Event Listener,用于侦听Presto引擎执行查询时发生的事件,并作出相应的处理。我们可以利用该功能实现诸如自定义日志记录、调试和性能分析插件,帮助我们更好的运维Presto集群。但是不同于Hive Hook的是,在Presto集群中,一次只能有一个Event Listener处于活动状态。
Event Listener作为Plugin监听以下事件:
- Query Creation(查询建立相关信息)
- Query completion (success or failure)(查询执行相关信息,包含成功查询的细节信息,失败查询的错误码等信息)
- Split completion (success or failure)(split执行信息,同理包含成功和失败的细节信息)
了解Hook及Listener模式的朋友对于其步骤应该很清楚了,我们只需要:
- 实现Presto Event Listener和EventListenerFactory接口。
- 正确的打包我们的jar。
- 部署,放到Presto指定目录,修改配置文件。
接口
- 实现EventListener,该类是我们的核心逻辑所在,供包含上面所说的三个事件:
public interface EventListener
{
//query创建的详细信息
default void queryCreated(QueryCreatedEvent queryCreatedEvent)
{
}
//query执行的详细信息
default void queryCompleted(QueryCompletedEvent queryCompletedEvent)
{
}
//split执行的详细信息
default void splitCompleted(SplitCompletedEvent splitCompletedEvent)
{
}
}
- 实现EventListenerFactory创建我们自己实现的EventListener
- 实现Plugin接口,实现getEventListenerFactories()方法,获取我们自己实现的EventListenerFactory
- 添加配置信息,为etc/event-listener.properties。其中event-listener.name为必备属性,其他属性为我们plugin所需要的信息。
示例
由于集群运维的需要,先需要将用户的查询历史、查询花费的时间等信息进行统计,以便于后续对各个业务的查询进行优先级分级和评分,方便后续Presto集群稳定性易用性的维护。这里给出一个简单的将这些信息存储到Mysql数据库的样例。
Maven Pom
com.facebook.presto
presto-spi
0.220
compile
QueryEventListenerFactory
public class QueryEventListenerFactory implements EventListenerFactory {
@Override
public String getName() {
return "query-event-listener";
}
@Override
public EventListener create(Map config) {
if (!config.containsKey("jdbc.uri")) {
throw new RuntimeException("/etc/event-listener.properties file missing jdbc.uri");
}
if (!config.containsKey("jdbc.user")) {
throw new RuntimeException("/etc/event-listener.properties file missing jdbc.user");
}
if (!config.containsKey("jdbc.pwd")) {
throw new RuntimeException("/etc/event-listener.properties file missing jdbc.pwd");
}
return new QueryEventListener(config);
}
}
QueryEventPlugin
public class QueryEventPlugin implements Plugin {
@Override
public Iterable getEventListenerFactories() {
EventListenerFactory listenerFactory = new QueryEventListenerFactory();
return Arrays.asList(listenerFactory);
}
}
QueryEventListener
public class QueryEventListener implements EventListener {
private Map config;
private Connection connection;
public QueryEventListener(Map config) {
this.config = new HashMap<>();
this.config.putAll(config);
init();
}
private void init() {
try {
if (connection == null || !connection.isValid(10)) {
Class.forName("com.mysql.jdbc.Driver");
connection = DriverManager
.getConnection(config.get("jdbc.uri"), config.get("jdbc.user"), config.get("jdbc.pwd"));
}
} catch (SQLException | ClassNotFoundException e) {
e.printStackTrace();
}
}
@Override
public void queryCreated(QueryCreatedEvent queryCreatedEvent) {
}
@Override
public void queryCompleted(QueryCompletedEvent queryCompletedEvent) {
String queryId = queryCompletedEvent.getMetadata().getQueryId();
String querySql = queryCompletedEvent.getMetadata().getQuery();
String queryState = queryCompletedEvent.getMetadata().getQueryState();
String queryUser = queryCompletedEvent.getContext().getUser();
long createTime = queryCompletedEvent.getCreateTime().toEpochMilli();
long endTime = queryCompletedEvent.getEndTime().toEpochMilli();
long startTime = queryCompletedEvent.getExecutionStartTime().toEpochMilli();
//insert into query execution table
long analysisTime = queryCompletedEvent.getStatistics().getAnalysisTime().orElse(Duration.ZERO)
.toMillis();
long cpuTime = queryCompletedEvent.getStatistics().getCpuTime().toMillis();
long queuedTime = queryCompletedEvent.getStatistics().getQueuedTime().toMillis();
long wallTime = queryCompletedEvent.getStatistics().getWallTime().toMillis();
int completedSplits = queryCompletedEvent.getStatistics().getCompletedSplits();
double cumulativeMemory = queryCompletedEvent.getStatistics().getCumulativeMemory();
long outputBytes = queryCompletedEvent.getStatistics().getOutputBytes();
long outputRows = queryCompletedEvent.getStatistics().getOutputRows();
long totalBytes = queryCompletedEvent.getStatistics().getTotalBytes();
long totalRows = queryCompletedEvent.getStatistics().getTotalRows();
long writtenBytes = queryCompletedEvent.getStatistics().getWrittenBytes();
long writtenRows = queryCompletedEvent.getStatistics().getWrittenRows();
//insert into query info table
queryCompletedEvent.getFailureInfo().ifPresent(queryFailureInfo -> {
int code = queryFailureInfo.getErrorCode().getCode();
String name = queryFailureInfo.getErrorCode().getName();
String failureType = queryFailureInfo.getFailureType().orElse("").toUpperCase();
String failureHost = queryFailureInfo.getFailureHost().orElse("").toUpperCase();
String failureMessage = queryFailureInfo.getFailureMessage().orElse("").toUpperCase();
String failureTask = queryFailureInfo.getFailureTask().orElse("").toUpperCase();
String failuresJson = queryFailureInfo.getFailuresJson();
// insert into failed query table
});
}
@Override
public void splitCompleted(SplitCompletedEvent splitCompletedEvent) {
long createTime = splitCompletedEvent.getCreateTime().toEpochMilli();
long endTime = splitCompletedEvent.getEndTime().orElse(Instant.MIN).toEpochMilli();
String payload = splitCompletedEvent.getPayload();
String queryId = splitCompletedEvent.getQueryId();
String stageId = splitCompletedEvent.getStageId();
long startTime = splitCompletedEvent.getStartTime().orElse(Instant.MIN).toEpochMilli();
String taskId = splitCompletedEvent.getTaskId();
long completedDataSizeBytes = splitCompletedEvent.getStatistics().getCompletedDataSizeBytes();
long completedPositions = splitCompletedEvent.getStatistics().getCompletedPositions();
long completedReadTime = splitCompletedEvent.getStatistics().getCompletedReadTime().toMillis();
long cpuTime = splitCompletedEvent.getStatistics().getCpuTime().toMillis();
long queuedTime = splitCompletedEvent.getStatistics().getQueuedTime().toMillis();
long wallTime = splitCompletedEvent.getStatistics().getWallTime().toMillis();
//insert into stage info table
}
}
打包
- Presto使用服务提供者接口(SPI)来扩展Presto。Presto使用SPI加载连接器,功能,类型和系统访问控制。SPI通过元数据文件加载。我们还需要创建
src/main/resources/META-INF/services/com.facebook.presto.spi.Plugin
元数据文件。该文件应包含我们插件的类名如:com.ji3jin.presto.listener.QueryEventListener
- 执行
mvn clean install
打包
部署
- 创建配置文件etc/event-listener.properties
event-listener.name=query-event-listener
jdbc.uri=jdbc:mysql://localhost:3306/presto_monitor
jdbc.user=presto
jdbc.pwd=presto123
- 在presto根目录下创建
query-event-listener
目录,名称与我们上面event listener的name一致 - 将我们的jar包和mysql connector的jar包拷贝到上面创建的目录
- 重新启动Presto服务即可
好了,现在你可以执行查询,然后就可以在Mysql中看到你的查询历史和相关时间的统计信息了。如果你目前的工作对此也有需要,还等什么,快动手实现一个吧。