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Posted to user-zh@flink.apache.org by smq <37...@qq.com> on 2021/03/10 05:37:26 UTC
回复:MapState 无法更新问题
可以贴个完整的代码吗
------------------ 原始邮件 ------------------
发件人: chaos <jinhshi@163.com>
发送时间: 2021年3月10日 12:51
收件人: user-zh <user-zh@flink.apache.org>
主题: 回复:MapState 无法更新问题
你好,我在使用广播流的时候定义了一个MapState,并在逻辑处理中往其中放数据,但是我始终没法成功更新其值,忘解惑。
定义:
private val carEfenceState: MapState[String, Boolean] = new
MapStateDescriptor[String, Boolean]("carEfenceState", classOf[String],
classOf[Boolean])
存值:
carEfenceState.put(mapKey, true)
取值:
carEfenceState.get(mapKey)
取到的值始终为 false.
Thanks in advance!
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回复: 回复:MapState 无法更新问题
Posted by 明启 孙 <37...@qq.com>.
A read-only view of the {@link BroadcastState}.
*
* <p>Although read-only, the user code should not modify the value returned by the {@link
* #get(Object)} or the entries of the immutable iterator returned by the {@link
* #immutableEntries()}, as this can lead to inconsistent states. The reason for this is that we do
* not create extra copies of the elements for performance reasons.
*
* @param <K> The key type of the elements in the {@link ReadOnlyBroadcastState}.
* @param <V> The value type of the elements in the {@link ReadOnlyBroadcastState}.
*/
这是源码中对ReadOnlyBroadcastState的描述,希望对你有帮助
smq
发件人: chaos
发送时间: 2021年3月10日 14:29
收件人: user-zh@flink.apache.org
主题: Re: 回复:MapState 无法更新问题
主要代码如下:
class getRule extends KeyedBroadcastProcessFunction[String,
KafkaStreamSource, List[Rule], KafkaStreamSource] {
private var carEfenceState: MapState[String, Boolean] = _
override def open(parameters: Configuration): Unit = {
carEfenceState = getRuntimeContext.getMapState(new
MapStateDescriptor[String, Boolean]("carEfenceState", classOf[String],
classOf[Boolean]))
}
override def processBroadcastElement(in2: List[Rule], context:
KeyedBroadcastProcessFunction[String, KafkaStreamSource, List[Rule],
KafkaStreamSource]#Context, collector: Collector[KafkaStreamSource]): Unit =
{
context.getBroadcastState(ruleStateDescriptor).put("rules", in2)
}
override def processElement(kafkaSource: KafkaStreamSource,
readOnlyContext: KeyedBroadcastProcessFunction[String, KafkaStreamSource,
List[Rule], KafkaStreamSource]#ReadOnlyContext, collector:
Collector[KafkaStreamSource]): Unit = {
val ruleIterator =
readOnlyContext.getBroadcastState(ruleStateDescriptor).immutableEntries().iterator()
while (ruleIterator.hasNext) {
val ruleMap: Map.Entry[String, List[Rule]] = ruleIterator.next()
val ruleList: List[Rule] = ruleMap.getValue
for (rule <- ruleList) {
val mapKey = kafkaSource.vno + rule.id
val tempState = carEfenceState.get(mapKey)
val currentState = if (tempState != null) tempState else false
// 业务逻辑
if (!currentState) {
...
carEfenceState.put(mapKey, true)
...
} else if (currentState) {
...
carEfenceState.remove(mapKey)
...
}
}
}
}
}
--
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c
Re: 回复: 回复:MapState 无法更新问题
Posted by chaos <ji...@163.com>.
感谢回复,问题已解决。
解决方式:
参照官网的一个例子将状态的获取放在 processElement 内部。
private val eFenceMapStateDesc = new MapStateDescriptor[String,
Boolean]("carEfenceState", classOf[String], classOf[Boolean])
private val DbIdMapStateDesc = new MapStateDescriptor[String,
Long]("eFenceCarDbIdState", classOf[String], classOf[Long])
override def processElement(...){
val eFenceMapState = getRuntimeContext.getMapState(eFenceMapStateDesc)
val dbIdMapState = getRuntimeContext.getMapState(DbIdMapStateDesc)
....
}
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回复: 回复:MapState 无法更新问题
Posted by 明启 孙 <37...@qq.com>.
你虽然调整了实现方法的顺序,但是这个程序执行顺序还是先执行processElement(),后执行processBroadcastElement()
发件人: chaos
发送时间: 2021年3月10日 14:29
收件人: user-zh@flink.apache.org
主题: Re: 回复:MapState 无法更新问题
主要代码如下:
class getRule extends KeyedBroadcastProcessFunction[String,
KafkaStreamSource, List[Rule], KafkaStreamSource] {
private var carEfenceState: MapState[String, Boolean] = _
override def open(parameters: Configuration): Unit = {
carEfenceState = getRuntimeContext.getMapState(new
MapStateDescriptor[String, Boolean]("carEfenceState", classOf[String],
classOf[Boolean]))
}
override def processBroadcastElement(in2: List[Rule], context:
KeyedBroadcastProcessFunction[String, KafkaStreamSource, List[Rule],
KafkaStreamSource]#Context, collector: Collector[KafkaStreamSource]): Unit =
{
context.getBroadcastState(ruleStateDescriptor).put("rules", in2)
}
override def processElement(kafkaSource: KafkaStreamSource,
readOnlyContext: KeyedBroadcastProcessFunction[String, KafkaStreamSource,
List[Rule], KafkaStreamSource]#ReadOnlyContext, collector:
Collector[KafkaStreamSource]): Unit = {
val ruleIterator =
readOnlyContext.getBroadcastState(ruleStateDescriptor).immutableEntries().iterator()
while (ruleIterator.hasNext) {
val ruleMap: Map.Entry[String, List[Rule]] = ruleIterator.next()
val ruleList: List[Rule] = ruleMap.getValue
for (rule <- ruleList) {
val mapKey = kafkaSource.vno + rule.id
val tempState = carEfenceState.get(mapKey)
val currentState = if (tempState != null) tempState else false
// 业务逻辑
if (!currentState) {
...
carEfenceState.put(mapKey, true)
...
} else if (currentState) {
...
carEfenceState.remove(mapKey)
...
}
}
}
}
}
--
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c
Re: 回复:MapState 无法更新问题
Posted by chaos <ji...@163.com>.
你好,
主要代码如下:
class getRule extends KeyedBroadcastProcessFunction[String,
KafkaStreamSource, List[Rule], KafkaStreamSource] {
private var carEfenceState: MapState[String, Boolean] = _
override def open(parameters: Configuration): Unit = {
carEfenceState = getRuntimeContext.getMapState(new
MapStateDescriptor[String, Boolean]("carEfenceState", classOf[String],
classOf[Boolean]))
}
override def processBroadcastElement(in2: List[Rule], context:
KeyedBroadcastProcessFunction[String, KafkaStreamSource, List[Rule],
KafkaStreamSource]#Context, collector: Collector[KafkaStreamSource]): Unit =
{
context.getBroadcastState(ruleStateDescriptor).put("rules", in2)
}
override def processElement(kafkaSource: KafkaStreamSource,
readOnlyContext: KeyedBroadcastProcessFunction[String, KafkaStreamSource,
List[Rule], KafkaStreamSource]#ReadOnlyContext, collector:
Collector[KafkaStreamSource]): Unit = {
val ruleIterator =
readOnlyContext.getBroadcastState(ruleStateDescriptor).immutableEntries().iterator()
while (ruleIterator.hasNext) {
val ruleMap: Map.Entry[String, List[Rule]] = ruleIterator.next()
val ruleList: List[Rule] = ruleMap.getValue
for (rule <- ruleList) {
val mapKey = kafkaSource.vno + rule.id
val tempState = carEfenceState.get(mapKey)
val currentState = if (tempState != null) tempState else false
// 业务逻辑
if (!currentState) {
...
carEfenceState.put(mapKey, true)
...
} else if (currentState) {
...
carEfenceState.remove(mapKey)
...
}
}
}
}
}
--
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