Mit Sammlungen den Überblick behalten
Sie können Inhalte basierend auf Ihren Einstellungen speichern und kategorisieren.
In den folgenden Abschnitten wird beschrieben, wie Sie eine AlloyDB for PostgreSQL-Datenbank konfigurieren.
Verbindung zwischen Datastream und AlloyDB einrichten
Damit Datastream eine Verbindung zur AlloyDB-Instanz herstellen kann, müssen Sie im Nutzerprojekt einen TCP-Proxy einrichten. Das TCP-Proxy-Image ist für alle Nutzer öffentlich verfügbar.
Starten Sie den Proxy-Container:
Aktivieren Sie Cloud Shell im Nutzerprojekt.
Führen Sie das folgende Script aus, um den TCP-Proxy zu erstellen und das Bridge-Netzwerk zu deaktivieren, um Verbindungsprobleme zu vermeiden:
Aktivieren Sie die logische Decodierung für die primäre AlloyDB-Instanz. Legen Sie in Google Cloudden Wert für das alloydb.logical_decoding-Flag auf ON fest. Informationen zum Aktualisieren der Datenbank-Flags finden Sie unter Datenbank-Flags einer Instanz konfigurieren.
Stellen Sie über die TCP-Proxy-IP-Adresse eine Verbindung zur AlloyDB-Instanz her, indem Sie den folgenden Befehl von einer beliebigen VM im selben VPC ausführen:
psql-hPROXY_IP\-UDB_USER\-dDB_NAME
Ersetzen Sie Folgendes:
PROXY_IP: Die IP-Adresse des TCP-Proxys.
DB_USER: Der Nutzername für die AlloyDB-Datenbank.
DB_NAME: Der Name der AlloyDB-Datenbank.
Führen Sie den folgenden Befehl aus, um Ihrem Datenbanknutzer Replikationsberechtigungen zu gewähren:
ALTER USER DB_USER WITH REPLICATION;
Erstellen Sie eine Publikation. Wir empfehlen, eine Publikation nur für die Tabellen zu erstellen, die Sie replizieren möchten. So kann Datastream nur die relevanten Daten lesen und die Belastung der Datenbank und von Datastream wird verringert:
CREATE PUBLICATION PUBLICATION_NAME
FOR TABLE SCHEMA1.TABLE1, SCHEMA2.TABLE2;
Ersetzen Sie Folgendes:
PUBLICATION_NAME: Der Name Ihrer Publikation. Sie müssen diesen Namen angeben, wenn Sie einen Stream im Assistenten zum Erstellen von Datastream-Streams erstellen.
SCHEMA: Der Name des Schemas, das die Tabelle enthält.
TABLE: Der Name der Tabelle, die Sie replizieren möchten.
Sie können auch eine Publikation für alle Tabellen in Ihrer Datenbank erstellen. Beachten Sie, dass durch diesen Ansatz sowohl die Quelldatenbank als auch Datastream stärker belastet werden:
CREATE PUBLICATION PUBLICATION_NAME FOR ALL TABLES;
Erstellen Sie mit dem folgenden Befehl einen Replikationsslot.
REPLICATION_SLOT_NAME: Der Name des Replikationsslots.
Sie müssen diesen Namen angeben, wenn Sie einen Stream im Assistenten zum Erstellen von Datastream-Streams erstellen.
Datastream-Nutzer erstellen
Geben Sie den folgenden PostgreSQL-Befehl ein, um einen Datastream-Nutzer zu erstellen:
CREATE USER USER_NAME WITH REPLICATION LOGIN PASSWORD 'USER_PASSWORD';
Ersetzen Sie Folgendes:
USER_NAME: Der Name des Datastream-Nutzers, den Sie erstellen möchten.
USER_PASSWORD: Das Anmeldepasswort für den Datastream-Nutzer, den Sie erstellen möchten.
Gewähren Sie dem erstellten Nutzer die folgenden Berechtigungen:
GRANT SELECT ON ALL TABLES IN SCHEMA SCHEMA_NAME TO USER_NAME;
GRANT USAGE ON SCHEMA SCHEMA_NAME TO USER_NAME;
ALTER DEFAULT PRIVILEGES IN SCHEMA SCHEMA_NAME GRANT SELECT ON TABLES TO USER_NAME;
Ersetzen Sie Folgendes:
SCHEMA_NAME: Der Name des Schemas, dem Sie die Berechtigungen gewähren möchten.
USER_NAME: Der Nutzer, dem Sie die Berechtigungen gewähren möchten.
[[["Leicht verständlich","easyToUnderstand","thumb-up"],["Mein Problem wurde gelöst","solvedMyProblem","thumb-up"],["Sonstiges","otherUp","thumb-up"]],[["Schwer verständlich","hardToUnderstand","thumb-down"],["Informationen oder Beispielcode falsch","incorrectInformationOrSampleCode","thumb-down"],["Benötigte Informationen/Beispiele nicht gefunden","missingTheInformationSamplesINeed","thumb-down"],["Problem mit der Übersetzung","translationIssue","thumb-down"],["Sonstiges","otherDown","thumb-down"]],["Zuletzt aktualisiert: 2025-09-04 (UTC)."],[[["\u003cp\u003eThis guide explains how to configure an AlloyDB for PostgreSQL database to work with Datastream, beginning with setting up a TCP proxy for connectivity.\u003c/p\u003e\n"],["\u003cp\u003eTo enable Datastream's connection to the AlloyDB instance, a TCP proxy must be launched in the consumer project using a provided script, replacing placeholders with appropriate values.\u003c/p\u003e\n"],["\u003cp\u003eLogical decoding must be enabled on the AlloyDB primary instance, along with granting replication privileges to a designated database user via the provided command, and creating a publication for tables to be replicated.\u003c/p\u003e\n"],["\u003cp\u003eA dedicated Datastream user must be created with specific privileges, including replication login and select permissions on tables and schemas, using the provided commands.\u003c/p\u003e\n"],["\u003cp\u003eAfter completing the setup, you can use the TCP proxy IP address for the connection profile, and create a stream in the Datastream stream creation wizard using the publication and replication slot names.\u003c/p\u003e\n"]]],[],null,["# Configure an AlloyDB for PostgreSQL database\n\nThe following sections cover how to configure an AlloyDB for PostgreSQL database.\n\nSet up connectivity between Datastream and AlloyDB\n--------------------------------------------------\n\nTo enable Datastream to connect to the AlloyDB instance, you need to set up a TCP proxy in the consumer project. The [TCP proxy image](http://gcr.io/dms-images/tcp-proxy) is publicly available to all customers.\n\n1. Launch the proxy container:\n\n 1. Activate Cloud Shell in the consumer project.\n 2. Run the following script to create the TCP proxy and disable bridge networking to avoid connectivity issues:\n\n gcloud compute instances create-with-container \\\n --zone=\u003cvar translate=\"no\"\u003eREGION_ID\u003c/var\u003e \u003cvar translate=\"no\"\u003eVM_NAME\u003c/var\u003e \\\n --container-image gcr.io/dms-images/tcp-proxy \\\n --tags=dms-tcp-proxy \\\n --container-env=SOURCE_CONFIG=\u003cvar translate=\"no\"\u003eALLOYDB_IP\u003c/var\u003e:\u003cvar translate=\"no\"\u003eALLOYDB_PORT\u003c/var\u003e \\\n --can-ip-forward \\\n --network=\u003cvar translate=\"no\"\u003eSOURCE_AND_DEST_VPC\u003c/var\u003e \\\n --machine-type=\u003cvar translate=\"no\"\u003eVM_TIER\u003c/var\u003e \\\n --metadata=startup-script='#! /bin/bash\n mkdir -p /etc/docker\n cat \u003c\u003cEOF \u003e /etc/docker/daemon.json\n {\"bridge\":\"none\"}\n EOF\n systemctl restart docker'\n\n Replace the following:\n - \u003cvar translate=\"no\"\u003eREGION_ID\u003c/var\u003e: The region in which you want to create the TCP proxy.\n - \u003cvar translate=\"no\"\u003eVM_NAME\u003c/var\u003e: The name of the virtual machine.\n - \u003cvar translate=\"no\"\u003eALLOYDB_IP\u003c/var\u003e: The IP address of the AlloyDB for PostgreSQL instance.\n - \u003cvar translate=\"no\"\u003eALLOYDB_PORT\u003c/var\u003e: The port number of the AlloyDB for PostgreSQL instance.\n - \u003cvar translate=\"no\"\u003eSOURCE_AND_DEST_VPC\u003c/var\u003e: The VPC network to which the source and destination are connected.\n - \u003cvar translate=\"no\"\u003eVM_TIER\u003c/var\u003e: The type of your virtual machine.\n\n An example command with updated parameters: \n\n gcloud compute instances create-with-container \\\n --zone=us-central1-c ds-tcp-proxy \\\n --container-image gcr.io/dms-images/tcp-proxy \\\n --tags=ds-tcp-proxy \\\n --container-env=SOURCE_CONFIG=10.16.0.5:5432 \\\n --can-ip-forward \\\n --network=default \\\n --machine-type=e2-micro\n --metadata=startup-script='#! /bin/bash\n mkdir -p /etc/docker\n cat \u003c\u003cEOF \u003e /etc/docker/daemon.json\n {\"bridge\":\"none\"}\n EOF\n systemctl restart docker'\n\n | You may receive a prompt to authorize Cloud Shell. Click **AUTHORIZE**.\n2. Run the script to print the IP address of the TCP Proxy with the following inputs:\n\n gcloud compute instances describe \u003cvar translate=\"no\"\u003eVM_NAME\u003c/var\u003e \\\n --format=\"yaml(networkInterfaces[].networkIP)\" \\\n --zone=\u003cvar translate=\"no\"\u003eREGION_ID\u003c/var\u003e\n\n Replace the following:\n - \u003cvar translate=\"no\"\u003eVM_NAME\u003c/var\u003e: The name of your virtual machine.\n - \u003cvar translate=\"no\"\u003eREGION_ID\u003c/var\u003e: The region in which you created the TCP proxy.\n\n | Use this IP address in the Datastream [connection profile](/datastream/docs/create-connection-profiles#cp4postgresdb) configuration.\n3. (Optional) Create a firewall rule to limit ingress traffic to the TCP proxy:\n\n gcloud compute firewall-rules create \u003cvar translate=\"no\"\u003eFIREWALL_RULE_NAME\u003c/var\u003e \\\n --direction=INGRESS \\\n --priority=1000 \\\n --target-tags=dms-tcp-proxy \\\n --network=\u003cvar translate=\"no\"\u003eSOURCE_VPC\u003c/var\u003e \\\n --action=ALLOW \\\n --rules=tcp:\u003cvar translate=\"no\"\u003eALLOYDB_PORT\u003c/var\u003e \\\n --source-ranges=\u003cvar translate=\"no\"\u003eIP_RANGE\u003c/var\u003e\n\n Replace the following:\n - \u003cvar translate=\"no\"\u003eFIREWALL_RULE_NAME\u003c/var\u003e: The name of your firewall rule.\n - \u003cvar translate=\"no\"\u003eSOURCE_VPC\u003c/var\u003e: The VPC network to which your source is connected.\n - \u003cvar translate=\"no\"\u003eALLOYDB_PORT\u003c/var\u003e: The port number of the AlloyDB for PostgreSQL instance.\n - \u003cvar translate=\"no\"\u003eIP_RANGE\u003c/var\u003e: The IP address range to which you want to limit ingress traffic.\n\n An example command to allow ingress traffic from all IP addresses: \n\n gcloud compute firewall-rules create ds-proxy1 \\\n --direction=INGRESS \\\n --priority=1000 \\\n --target-tags=ds-tcp-proxy \\\n --network=default \\\n --action=ALLOW \\\n --rules=tcp:5432\n\nConfigure AlloyDB for replication\n---------------------------------\n\n1. Enable logical decoding for the AlloyDB primary instance. In Google Cloud, set\n the value for the `alloydb.logical_decoding` flag to **ON** . For information about\n updating the database flags, see [Configure an instance's database flags](/alloydb/docs/instance-configure-database-flags).\n\n | **Note:** Updating the `alloydb.logical_decoding` flag restarts the instance.\n2. Connect to the AlloyDB instance using the TCP proxy IP address by running the\n following command from any VM on the same VPC:\n\n psql -h \u003cvar translate=\"no\"\u003ePROXY_IP\u003c/var\u003e \\\n -U \u003cvar translate=\"no\"\u003eDB_USER\u003c/var\u003e \\\n -d \u003cvar translate=\"no\"\u003eDB_NAME\u003c/var\u003e\n\n Replace the following:\n - \u003cvar translate=\"no\"\u003ePROXY_IP\u003c/var\u003e: The IP address of the TCP proxy.\n - \u003cvar translate=\"no\"\u003eDB_USER\u003c/var\u003e: The username for the AlloyDB database.\n - \u003cvar translate=\"no\"\u003eDB_NAME\u003c/var\u003e: The AlloyDB database name.\n3. Run the following command to grant replication privileges to your database user:\n\n ```\n ALTER USER DB_USER WITH REPLICATION;\n ```\n4. Create a publication. We recommend that you create a publication only for the\n tables that you want to replicate. This allows Datastream to read-only\n the relevant data, and lowers the load on the database and Datastream:\n\n ```\n CREATE PUBLICATION PUBLICATION_NAME\n FOR TABLE SCHEMA1.TABLE1, SCHEMA2.TABLE2;\n ```\n\n Replace the following:\n - \u003cvar translate=\"no\"\u003ePUBLICATION_NAME\u003c/var\u003e: The name of your publication. You'll need to provide this name when you create a stream in the Datastream stream creation wizard.\n - \u003cvar translate=\"no\"\u003eSCHEMA\u003c/var\u003e: The name of the schema that contains the table.\n - \u003cvar translate=\"no\"\u003eTABLE\u003c/var\u003e: The name of the table that you want to replicate.\n\n You can also create a publication for all tables in your database. Note that\n this approach increases the load on both the source database and Datastream: \n\n ```\n CREATE PUBLICATION PUBLICATION_NAME FOR ALL TABLES;\n ```\n | For PostgreSQL 15 and later, you can create a publication for all tables in a schema. This approach lets you replicate changes for tables in the specified list of schemas, including tables that you create in the future: \n |\n | ```\n | CREATE PUBLICATION PUBLICATION_NAME\n | FOR TABLES IN SCHEMA SCHEMA1, SCHEMA2;\n | ```\n5. Create a replication slot by executing the following command.\n\n ```\n SELECT PG_CREATE_LOGICAL_REPLICATION_SLOT('REPLICATION_SLOT_NAME', 'pgoutput');\n ```\n\n Replace the following:\n - \u003cvar translate=\"no\"\u003eREPLICATION_SLOT_NAME\u003c/var\u003e: The name of your replication slot. You'll need to provide this name when you create a stream in the Datastream stream creation wizard.\n\nCreate a Datastream user\n------------------------\n\n1. To create a Datastream user, enter the following PostgreSQL command:\n\n ```\n CREATE USER USER_NAME WITH REPLICATION LOGIN PASSWORD 'USER_PASSWORD';\n ```\n\n Replace the following:\n - \u003cvar translate=\"no\"\u003eUSER_NAME\u003c/var\u003e: The name of the Datastream user that you want to create.\n - \u003cvar translate=\"no\"\u003eUSER_PASSWORD\u003c/var\u003e: The login password for the Datastream user that you want to create.\n2. Grant the following privileges to the user you created:\n\n ```\n GRANT SELECT ON ALL TABLES IN SCHEMA SCHEMA_NAME TO USER_NAME;\n GRANT USAGE ON SCHEMA SCHEMA_NAME TO USER_NAME;\n ALTER DEFAULT PRIVILEGES IN SCHEMA SCHEMA_NAME GRANT SELECT ON TABLES TO USER_NAME;\n ```\n\n Replace the following:\n - \u003cvar translate=\"no\"\u003eSCHEMA_NAME\u003c/var\u003e: The name of the schema to which you want to grant the privileges.\n - \u003cvar translate=\"no\"\u003eUSER_NAME\u003c/var\u003e: The user to whom you want to grant the privileges.\n\n | The first command might display warnings, however it is safe to ignore them.\n\nWhat's next\n-----------\n\n- Learn more about how Datastream works with [PostgreSQL sources](/datastream/docs/sources-postgresql)."]]