[GitHub] bahir issue #13: [BAHIR-39] Add SQL Streaming MQTT support.
Github user frreiss commented on the issue: https://github.com/apache/bahir/pull/13 LGTM. --- If your project is set up for it, you can reply to this email and have your reply appear on GitHub as well. If your project does not have this feature enabled and wishes so, or if the feature is enabled but not working, please contact infrastructure at infrastruct...@apache.org or file a JIRA ticket with INFRA. ---
[GitHub] bahir pull request #13: [BAHIR-39] Add SQL Streaming MQTT support.
Github user frreiss commented on a diff in the pull request:
https://github.com/apache/bahir/pull/13#discussion_r73422375
--- Diff:
sql-streaming-mqtt/src/main/scala/org/apache/bahir/sql/streaming/mqtt/MQTTStreamSource.scala
---
@@ -0,0 +1,191 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License. You may obtain a copy of the License at
+ *
+ *http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.apache.bahir.sql.streaming.mqtt
+
+import java.sql.Timestamp
+import java.text.SimpleDateFormat
+import java.util.Calendar
+import java.util.concurrent.CountDownLatch
+
+import scala.collection.concurrent.TrieMap
+import scala.collection.mutable.ArrayBuffer
+import scala.util.{Failure, Success, Try}
+
+import org.apache.bahir.utils.Logging
+import org.eclipse.paho.client.mqttv3._
+import org.eclipse.paho.client.mqttv3.persist.{MemoryPersistence,
MqttDefaultFilePersistence}
+
+import org.apache.spark.sql.{DataFrame, SQLContext}
+import org.apache.spark.sql.execution.streaming.{LongOffset, Offset,
Source}
+import org.apache.spark.sql.sources.{DataSourceRegister,
StreamSourceProvider}
+import org.apache.spark.sql.types.{StringType, StructField, StructType,
TimestampType}
+
+
+object MQTTStreamConstants {
+
+ val DATE_FORMAT = new SimpleDateFormat("-MM-dd HH:mm:ss")
+
+ val SCHEMA_DEFAULT = StructType(StructField("value", StringType)
+:: StructField("timestamp", TimestampType) :: Nil)
+}
+
+class MQTTTextStreamSource(brokerUrl: String, persistence:
MqttClientPersistence,
+topic: String, clientId: String, messageParser: Array[Byte] =>
(String, Timestamp),
+sqlContext: SQLContext) extends Source with Logging {
+
+ override def schema: StructType = MQTTStreamConstants.SCHEMA_DEFAULT
+
+ private val store = new LocalMessageStore(persistence,
sqlContext.sparkContext.getConf)
+
+ private val messages = new TrieMap[Int, (String, Timestamp)]
+
+ private val initLock = new CountDownLatch(1)
+
+ private var offset = 0
+
+ private var client: MqttClient = _
+
+ private def fetchLastProcessedOffset(): Int = {
+Try(store.maxProcessedOffset) match {
+ case Success(x) =>
+log.info(s"Recovering from last stored offset $x")
+x
+ case Failure(e) => 0
+}
+ }
+
+ initialize()
+ private def initialize(): Unit = {
+
+client = new MqttClient(brokerUrl, clientId, persistence)
+val mqttConnectOptions: MqttConnectOptions = new MqttConnectOptions()
+mqttConnectOptions.setAutomaticReconnect(true)
+// This is required to support recovery. TODO: configurable ?
+mqttConnectOptions.setCleanSession(false)
+
+val callback = new MqttCallbackExtended() {
+
+ override def messageArrived(topic_ : String, message: MqttMessage):
Unit = synchronized {
+initLock.await() // Wait for initialization to complete.
+val temp = offset + 1
+messages.put(temp, messageParser(message.getPayload))
+offset = temp
+log.trace(s"Message arrived, $topic_ $message")
+ }
+
+ override def deliveryComplete(token: IMqttDeliveryToken): Unit = {
--- End diff --
I feel like this callback probably needs to do something to ensure that
there are no duplicate or out of order messages in the message buffer. What is
the interaction between these two callbacks (messageArrived/deliveryComplete)
and the different QoS levels in MQTT?
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[GitHub] bahir pull request #13: [BAHIR-39] Add SQL Streaming MQTT support.
Github user frreiss commented on a diff in the pull request:
https://github.com/apache/bahir/pull/13#discussion_r73422074
--- Diff:
sql-streaming-mqtt/src/main/scala/org/apache/bahir/sql/streaming/mqtt/MQTTStreamSource.scala
---
@@ -0,0 +1,191 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License. You may obtain a copy of the License at
+ *
+ *http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.apache.bahir.sql.streaming.mqtt
+
+import java.sql.Timestamp
+import java.text.SimpleDateFormat
+import java.util.Calendar
+import java.util.concurrent.CountDownLatch
+
+import scala.collection.concurrent.TrieMap
+import scala.collection.mutable.ArrayBuffer
+import scala.util.{Failure, Success, Try}
+
+import org.apache.bahir.utils.Logging
+import org.eclipse.paho.client.mqttv3._
+import org.eclipse.paho.client.mqttv3.persist.{MemoryPersistence,
MqttDefaultFilePersistence}
+
+import org.apache.spark.sql.{DataFrame, SQLContext}
+import org.apache.spark.sql.execution.streaming.{LongOffset, Offset,
Source}
+import org.apache.spark.sql.sources.{DataSourceRegister,
StreamSourceProvider}
+import org.apache.spark.sql.types.{StringType, StructField, StructType,
TimestampType}
+
+
+object MQTTStreamConstants {
+
+ val DATE_FORMAT = new SimpleDateFormat("-MM-dd HH:mm:ss")
+
+ val SCHEMA_DEFAULT = StructType(StructField("value", StringType)
+:: StructField("timestamp", TimestampType) :: Nil)
+}
+
+class MQTTTextStreamSource(brokerUrl: String, persistence:
MqttClientPersistence,
+topic: String, clientId: String, messageParser: Array[Byte] =>
(String, Timestamp),
+sqlContext: SQLContext) extends Source with Logging {
+
+ override def schema: StructType = MQTTStreamConstants.SCHEMA_DEFAULT
+
+ private val store = new LocalMessageStore(persistence,
sqlContext.sparkContext.getConf)
+
+ private val messages = new TrieMap[Int, (String, Timestamp)]
+
+ private val initLock = new CountDownLatch(1)
+
+ private var offset = 0
+
+ private var client: MqttClient = _
+
+ private def fetchLastProcessedOffset(): Int = {
+Try(store.maxProcessedOffset) match {
+ case Success(x) =>
+log.info(s"Recovering from last stored offset $x")
+x
+ case Failure(e) => 0
+}
+ }
+
+ initialize()
+ private def initialize(): Unit = {
+
+client = new MqttClient(brokerUrl, clientId, persistence)
+val mqttConnectOptions: MqttConnectOptions = new MqttConnectOptions()
+mqttConnectOptions.setAutomaticReconnect(true)
+// This is required to support recovery. TODO: configurable ?
+mqttConnectOptions.setCleanSession(false)
+
+val callback = new MqttCallbackExtended() {
+
+ override def messageArrived(topic_ : String, message: MqttMessage):
Unit = synchronized {
--- End diff --
Does MQTT guarantee that this method will be called exactly once, even if
the client or server crashes and is restarted?
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