flink metric用来对外暴露系统内部的一些运行指标，比如flink框架运行时的JVM相关配置，或者基于flink开发的项目。
监控类型
flink提供了Counter, Gauge, Histogram and Meter四种类型的指标。我们通过继承RichFunction拿到MetricGroup，并向其中填充指标。
Counter：
用与存储数值类型，比如统计数据输入、输出总数量。
public class MyMapper extends RichMapFunction<String, String> {
private transient Counter counter;
@Override
public void open(Configuration config) {
this.counter = getRuntimeContext()
.getMetricGroup()
.counter("myCounter");
}
@Override
public String map(String value) throws Exception {
this.counter.inc();
return value;
}
}
Gauge:
可以用来存储任何类型，前提要实现org.apache.flink.metrics.Gauge接口，重写getValue方法，如果返回类型为Object则该类需要重写toString方法。
有些场景下，需要根据业务计算出指标，则Gauge使用起来更灵活。
public class MyMapper extends RichMapFunction<String, String> {
private transient int valueToExpose = 0;
@Override
public void open(Configuration config) {
getRuntimeContext()
.getMetricGroup()
.gauge("MyGauge", new Gauge<Integer>() {
@Override
public Integer getValue() {
return valueToExpose;
}
});
}
@Override
public String map(String value) throws Exception {
valueToExpose++;
return value;
}
}
Meter：
用来计算平均速率，直接使用其子类MeterView更方便一些。
public class MyMapper extends RichMapFunction<Long, Long> {
private transient Counter numInBytes;
private transient Meter meter;
@Override
public void open(Configuration config) {
this.meter = getRuntimeContext()
.getMetricGroup()
.meter("myMeter", new MeterView(numInBytes, 20));
}
@Override
public Long map(Long value) throws Exception {
numInBytes.inc(value);
return value;
}
}
添加自定义监控指标
以flink1.5的Kafka读取以及写入为例，添加rps、dirtyData等相关指标信息。�kafka读取和写入重点是先拿到RuntimeContex初始化指标，并传递给要使用的序列类，通过重写序列化和反序列化方法，来更新指标信息。
不加指标的kafka数据读取、写入Demo
public class FlinkEtlTest {
private static final Logger logger = LoggerFactory.getLogger(FlinkEtlTest.class);
public static void main(String[] args) throws Exception {
final ParameterTool params = ParameterTool.fromArgs(args);
String jobName = params.get("jobName");
StreamExecutionEnvironment env = StreamExecutionEnvironment.getExecutionEnvironment();
/** 设置kafka数据 */
String topic = "myTest01";
Properties props = new Properties();
props.setProperty("bootstrap.servers", "localhost:9092");
props.setProperty("zookeeper.quorum", "localhost:2181/kafka");
// 使用FlinkKafkaConsumer09以及SimpleStringSchema序列化类，读取kafka数据
FlinkKafkaConsumer09<String> consumer09 = new FlinkKafkaConsumer09(topic, new SimpleStringSchema(), props);
consumer09.setStartFromEarliest();
// 使用FlinkKafkaProducer09和SimpleStringSchema反序列化类，将数据写入kafka
String sinkBrokers = "localhost:9092";
FlinkKafkaProducer09<String> myProducer = new FlinkKafkaProducer09<>(sinkBrokers, "myTest01", new SimpleStringSchema());
DataStream<String> kafkaDataStream = env.addSource(consumer09);
kafkaDataStream = kafkaDataStream.map(str -> {
logger.info("map receive {}",str);
return str.toUpperCase();
});
kafkaDataStream.addSink(myProducer);
env.execute(jobName);
}
}
为kafka读取添加相关指标
- 继承FlinkKafkaConsumer09，获取它的RuntimeContext，使用当前MetricGroup初始化指标参数。
public class CustomerFlinkKafkaConsumer09<T> extends FlinkKafkaConsumer09<T> {
CustomerSimpleStringSchema customerSimpleStringSchema;
// 构造方法有多个
public CustomerFlinkKafkaConsumer09(String topic, DeserializationSchema valueDeserializer, Properties props) {
super(topic, valueDeserializer, props);
this.customerSimpleStringSchema = (CustomerSimpleStringSchema) valueDeserializer;
}
@Override
public void run(SourceContext sourceContext) throws Exception {
//将RuntimeContext传递给customerSimpleStringSchema
customerSimpleStringSchema.setRuntimeContext(getRuntimeContext());
// 初始化指标
customerSimpleStringSchema.initMetric();
super.run(sourceContext);
}
}
- 重写SimpleStringSchema类的反序列化方法，当数据流入时变更指标。
public class CustomerSimpleStringSchema extends SimpleStringSchema {
private static final Logger logger = LoggerFactory.getLogger(CustomerSimpleStringSchema.class);
public static final String DT_NUM_RECORDS_RESOVED_IN_COUNTER = "dtNumRecordsInResolve";
public static final String DT_NUM_RECORDS_RESOVED_IN_RATE = "dtNumRecordsInResolveRate";
public static final String DT_DIRTY_DATA_COUNTER = "dtDirtyData";
public static final String DT_NUM_BYTES_IN_COUNTER = "dtNumBytesIn";
public static final String DT_NUM_RECORDS_IN_RATE = "dtNumRecordsInRate";
public static final String DT_NUM_BYTES_IN_RATE = "dtNumBytesInRate";
public static final String DT_NUM_RECORDS_IN_COUNTER = "dtNumRecordsIn";
protected transient Counter numInResolveRecord;
//source RPS
protected transient Meter numInResolveRate;
//source dirty data
protected transient Counter dirtyDataCounter;
// tps
protected transient Meter numInRate;
protected transient Counter numInRecord;
//bps
protected transient Counter numInBytes;
protected transient Meter numInBytesRate;
private transient RuntimeContext runtimeContext;
public void initMetric() {
numInResolveRecord = runtimeContext.getMetricGroup().counter(DT_NUM_RECORDS_RESOVED_IN_COUNTER);
numInResolveRate = runtimeContext.getMetricGroup().meter(DT_NUM_RECORDS_RESOVED_IN_RATE, new MeterView(numInResolveRecord, 20));
dirtyDataCounter = runtimeContext.getMetricGroup().counter(DT_DIRTY_DATA_COUNTER);
numInBytes = runtimeContext.getMetricGroup().counter(DT_NUM_BYTES_IN_COUNTER);
numInRecord = runtimeContext.getMetricGroup().counter(DT_NUM_RECORDS_IN_COUNTER);
numInRate = runtimeContext.getMetricGroup().meter(DT_NUM_RECORDS_IN_RATE, new MeterView(numInRecord, 20));
numInBytesRate = runtimeContext.getMetricGroup().meter(DT_NUM_BYTES_IN_RATE , new MeterView(numInBytes, 20));
}
// 源表读取重写deserialize方法
@Override
public String deserialize(byte[] value) {
// 指标进行变更
numInBytes.inc(value.length);
numInResolveRecord.inc();
numInRecord.inc();
try {
return super.deserialize(value);
} catch (Exception e) {
dirtyDataCounter.inc();
}
return "";
}
public void setRuntimeContext(RuntimeContext runtimeContext) {
this.runtimeContext = runtimeContext;
}
}
- 新的API使用
CustomerFlinkKafkaConsumer09<String> consumer09 = new CustomerFlinkKafkaConsumer09(topic, new CustomerSimpleStringSchema(), props);
为kafka写入添加相关指标
- 继承FlinkKafkaProducer09类，重写open方法，拿到RuntimeContext，初始化指标信息传递给CustomerSinkStringSchema。
public class CustomerFlinkKafkaProducer09<T> extends FlinkKafkaProducer09<T> {
public static final String DT_NUM_RECORDS_OUT = "dtNumRecordsOut";
public static final String DT_NUM_RECORDS_OUT_RATE = "dtNumRecordsOutRate";
CustomerSinkStringSchema schema;
public CustomerFlinkKafkaProducer09(String brokerList, String topicId, SerializationSchema serializationSchema) {
super(brokerList, topicId, serializationSchema);
this.schema = (CustomerSinkStringSchema) serializationSchema;
}
@Override
public void open(Configuration configuration) {
producer = getKafkaProducer(this.producerConfig);
RuntimeContext ctx = getRuntimeContext();
Counter counter = ctx.getMetricGroup().counter(DT_NUM_RECORDS_OUT);
//Sink的RPS计算
MeterView meter = ctx.getMetricGroup().meter(DT_NUM_RECORDS_OUT_RATE, new MeterView(counter, 20));
// 将counter传递给CustomerSinkStringSchema
schema.setCounter(counter);
super.open(configuration);
}
}
- 重写SimpleStringSchema的序列化方法
public class CustomerSinkStringSchema extends SimpleStringSchema {
private static final Logger logger = LoggerFactory.getLogger(CustomerSinkStringSchema.class);
private Counter sinkCounter;
@Override
public byte[] serialize(String element) {
logger.info("sink data {}", element);
sinkCounter.inc();
return super.serialize(element);
}
public void setCounter(Counter counter) {
this.sinkCounter = counter;
}
}
- 新的kafkaSinkApi使用
CustomerFlinkKafkaProducer09<String> myProducer = new CustomerFlinkKafkaProducer09<>(sinkBrokers, "mqTest01", new CustomerSinkStringSchema());
这样就可以在监控框架里面看到采集的指标信息了，比如flink_taskmanager_job_task_operator_dtDirtyData指标，dtDirtyData是自己添加的指标，前面的字符串是operator默认使用的metricGroup。
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