mattyb149 commented on a change in pull request #4065: NIFI-4239 - Adding CaptureChangePostgreSQL processor to capture data changes (INSERT/UPDATE/DELETE) in PostgreSQL tables via Logical Replication. URL: https://github.com/apache/nifi/pull/4065#discussion_r383542001
########## File path: nifi-nar-bundles/nifi-cdc/nifi-cdc-postgresql-bundle/nifi-cdc-postgresql-processors/src/main/java/org/apache/nifi/cdc/postgresql/processors/CaptureChangePostgreSQL.java ########## @@ -0,0 +1,519 @@ +/* + * 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.nifi.cdc.postgresql.processors; + +import java.io.IOException; +import java.io.OutputStream; +import java.net.MalformedURLException; +import java.nio.charset.StandardCharsets; +import java.sql.Connection; +import java.sql.Driver; +import java.sql.DriverManager; +import java.sql.DriverPropertyInfo; +import java.sql.SQLException; +import java.sql.SQLFeatureNotSupportedException; +import java.util.ArrayList; +import java.util.Collections; +import java.util.HashMap; +import java.util.HashSet; +import java.util.LinkedList; +import java.util.List; +import java.util.Map; +import java.util.Properties; +import java.util.Set; +import java.util.concurrent.atomic.AtomicBoolean; +import java.util.logging.Logger; + +import org.apache.nifi.annotation.behavior.InputRequirement; +import org.apache.nifi.annotation.behavior.Stateful; +import org.apache.nifi.annotation.behavior.TriggerSerially; +import org.apache.nifi.annotation.behavior.WritesAttribute; +import org.apache.nifi.annotation.behavior.WritesAttributes; +import org.apache.nifi.annotation.documentation.CapabilityDescription; +import org.apache.nifi.annotation.documentation.Tags; +import org.apache.nifi.annotation.lifecycle.OnScheduled; +import org.apache.nifi.annotation.lifecycle.OnShutdown; +import org.apache.nifi.annotation.lifecycle.OnStopped; +import org.apache.nifi.cdc.CDCException; +import org.apache.nifi.cdc.postgresql.pgEasyReplication.ConnectionManager; +import org.apache.nifi.cdc.postgresql.pgEasyReplication.PGEasyReplication; +import org.apache.nifi.cdc.postgresql.pgEasyReplication.Event; +import org.apache.nifi.components.PropertyDescriptor; +import org.apache.nifi.components.state.Scope; +import org.apache.nifi.components.state.StateManager; +import org.apache.nifi.components.state.StateMap; +import org.apache.nifi.expression.ExpressionLanguageScope; +import org.apache.nifi.flowfile.FlowFile; +import org.apache.nifi.logging.ComponentLog; +import org.apache.nifi.processor.AbstractProcessor; +import org.apache.nifi.processor.ProcessContext; +import org.apache.nifi.processor.ProcessSession; +import org.apache.nifi.processor.ProcessorInitializationContext; +import org.apache.nifi.processor.Relationship; +import org.apache.nifi.processor.exception.ProcessException; +import org.apache.nifi.processor.io.OutputStreamCallback; +import org.apache.nifi.processor.util.StandardValidators; +import org.apache.nifi.reporting.InitializationException; +import org.apache.nifi.util.file.classloader.ClassLoaderUtils; + +/** + * A processor to retrieve Change Data Capture (CDC) events and send them as flow files. + */ +@TriggerSerially +@InputRequirement(InputRequirement.Requirement.INPUT_FORBIDDEN) +@Tags({ "sql", "jdbc", "cdc", "postgresql" }) +@CapabilityDescription("Retrieves Change Data Capture (CDC) events from a PostgreSQL database. CDC Events include INSERT, UPDATE, DELETE operations. Events " + + "are output as individual flow files ordered by the time at which the operation occurred. This processor use a replication connection to stream data and sql connection to snapshot.") +@Stateful(scopes = Scope.CLUSTER, description = "Information such as a 'pointer' to the current CDC event in the database is stored by this processor, such " + + "that it can continue from the same location if restarted.") +@WritesAttributes({ + @WritesAttribute(attribute = "last.lsn.received", description = "A Log Sequence Number (i.e. strictly increasing integer value) specifying the order " + + "of the CDC event flow file relative to the other event flow file(s)."), + @WritesAttribute(attribute = "mime.type", description = "The processor outputs flow file content in JSON format, and sets the mime.type attribute to " + "application/json") }) + +public class CaptureChangePostgreSQL extends AbstractProcessor { + // Relationships + public static final Relationship REL_SUCCESS = new Relationship.Builder().name("success").description("Successfully created FlowFile from CDC event.").build(); + // Properties + public static final PropertyDescriptor HOST = new PropertyDescriptor.Builder() + .name("cdc-postgresql-host") + .displayName("PostgreSQL Host") + .description("A list of hostname/port entries corresponding to nodes in a PostgreSQL cluster. The entries should be comma separated " + + "using a colon such as host1:port,host2:port,.... For example postgresql.myhost.com:5432. This processor will attempt to connect to " + + "the hosts in the list in order. If one node goes down and failover is enabled for the cluster, then the processor will connect " + + "to the active node (assuming its host entry is specified in this property. The default port for PostgreSQL connections is 5432.") + .required(true) + .addValidator(StandardValidators.NON_EMPTY_VALIDATOR) + .build(); + + public static final PropertyDescriptor DRIVER_NAME = new PropertyDescriptor.Builder() + .name("cdc-postgresql-driver-class") + .displayName("PostgreSQL Driver Class Name") + .description("The class name of the PostgreSQL database driver class") + .defaultValue("org.postgresql.Driver") + .required(true) + .addValidator(StandardValidators.NON_EMPTY_VALIDATOR) + .expressionLanguageSupported(ExpressionLanguageScope.VARIABLE_REGISTRY) + .build(); + + public static final PropertyDescriptor DRIVER_LOCATION = new PropertyDescriptor.Builder() + .name("cdc-postgresql-driver-locations") + .displayName("PostgreSQL Driver Location(s)") + .description("Comma-separated list of files/folders and/or URLs containing the PostgreSQL driver JAR and its dependencies (if any)." + + "For example '/var/tmp/postgresql-42.2.9.jar'") + .defaultValue(null) + .required(false) + .addValidator(StandardValidators.createListValidator(true, true, StandardValidators.createURLorFileValidator())) + .expressionLanguageSupported(ExpressionLanguageScope.VARIABLE_REGISTRY) + .build(); + + public static final PropertyDescriptor DATABASE_NAME = new PropertyDescriptor.Builder() + .name("cdc-postgresql-database") + .displayName("Database") + .description("Specifies the name of the database to connect to.") + .required(true) + .addValidator(StandardValidators.NON_EMPTY_VALIDATOR).build(); + + public static final PropertyDescriptor USERNAME = new PropertyDescriptor.Builder() + .name("cdc-postgresql-user") + .displayName("Username") + .description("Username to access PostgreSQL cluster.") + .required(true) + .addValidator(StandardValidators.NON_EMPTY_VALIDATOR) + .build(); + + public static final PropertyDescriptor PASSWORD = new PropertyDescriptor.Builder() + .name("cdc-postgresql-password") + .displayName("Password") + .description("Password to access PostgreSQL cluster.") + .required(false) + .sensitive(true) + .addValidator(StandardValidators.NON_EMPTY_VALIDATOR) + .build(); + + public static final PropertyDescriptor PUBLICATION = new PropertyDescriptor.Builder() + .name("cdc-postgresql-publication") + .displayName("Publication") + .description("PostgreSQL publication name. A publication is essentially a group of tables whose data changes are intended to be replicated through logical replication.") + .required(true) + .addValidator(StandardValidators.NON_EMPTY_VALIDATOR) + .build(); + + public static final PropertyDescriptor SLOT_NAME = new PropertyDescriptor.Builder() + .name("cdc-postgresql-slot-name") + .displayName("Slot Name") + .description("A unique, cluster-wide identifier for the replication slot") + .required(true) + .addValidator(StandardValidators.NON_EMPTY_VALIDATOR) + .build(); + + public static final PropertyDescriptor SNAPSHOT = new PropertyDescriptor.Builder() + .name("cdc-postgresql-snapshot") + .displayName("Make Snapshot") + .description("The initial data in existing subscribed tables are snapshotted and copied in a parallel instance of a special kind of apply " + + "process. This process will create its own temporary replication slot and copy the existing data. Once existing data is copied, " + + "the worker enters synchronization mode, which ensures that the table is brought up to a synchronized state with the main apply " + + "process by streaming any changes that happened during the initial data copy using standard logical replication. Once the " + + "synchronization is done, the control of the replication of the table is given back to the main apply process where the replication " + "continues as normal.") + .required(true) + .allowableValues("true", "false") + .defaultValue("false") + .addValidator(StandardValidators.BOOLEAN_VALIDATOR) + .build(); + + public static final PropertyDescriptor INCLUDE_BEGIN_COMMIT = new PropertyDescriptor.Builder() + .name("cdc-postgresql-include-begin-commit") + .displayName("Include Begin/Commit Events") + .description("Specifies whether to emit events corresponding to a BEGIN or COMMIT event. Set to true if the BEGIN/COMMIT events are necessary in the downstream flow, " + + "otherwise set to false, which suppresses generation of these events and can increase flow performance.") + .required(true) + .allowableValues("true", "false") + .defaultValue("false") + .addValidator(StandardValidators.BOOLEAN_VALIDATOR) + .build(); + + public static final PropertyDescriptor INIT_LSN = new PropertyDescriptor.Builder() + .name("cdc-postgresql-init-lsn") + .displayName("Initial Log Sequence Number - LSN") + .description("Specifies an initial Log Sequence Number - LSN to use if this processor's State does not have a current " + + "sequence identifier. If a Log Sequence Number - LSN is present in the processor's State, this property is ignored. Log Sequence Number - LSN are " + + "monotonically increasing integers that record the order of flow files generated by the processor. They can be used with the EnforceOrder " + + "processor to guarantee ordered delivery of CDC events.") + .required(false) + .addValidator(StandardValidators.POSITIVE_LONG_VALIDATOR) + .build(); + + public static final PropertyDescriptor DROP_SLOT_IF_EXISTS = new PropertyDescriptor.Builder() + .name("cdc-postgresql-drop-slot-if-exists") + .displayName("Drop If Exists Replication Slot") + .description("The initial data in existing subscribed tables are snapshotted and copied in a parallel instance of a special kind of apply " + + "process. This process will create its own temporary replication slot and copy the existing data. Once existing data is copied, " + + "the worker enters synchronization mode, which ensures that the table is brought up to a synchronized state with the main apply " + + "process by streaming any changes that happened during the initial data copy using standard logical replication. Once the " + + "synchronization is done, the control of the replication of the table is given back to the main apply process where the replication " + "continues as normal.") + .required(true) + .allowableValues("true", "false") + .defaultValue("false") + .addValidator(StandardValidators.BOOLEAN_VALIDATOR) + .build(); + + private List<PropertyDescriptor> descriptors; + private Set<Relationship> relationships; + + // Attribute keys + public static final String MIME_TYPE_ATTRIBUTE = "mime.type"; Review comment: You can use `CoreAttributes.MIME_TYPE.key()` here to avoid another constant ---------------------------------------------------------------- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. For queries about this service, please contact Infrastructure at: [email protected] With regards, Apache Git Services
