# Step 3: Test Spider Sharded Topology ## Overview This page details step 3 of the 3-step procedure "[Deploy Spider Sharded Topology](https://mariadb.com/docs/server/architecture/topologies/spider-sharded)". This step tests MariaDB Enterprise Spider. Interactive commands are detailed. Alternatively, the described operations can be performed using automation. ## Test Enterprise Server Service Use Systemd to test whether the MariaDB Enterprise Server service is running. This action is performed **on the Spider Node and each Data Node**. Check if the MariaDB Enterprise Server service is running by executing the following: ```bash $ systemctl status mariadb ``` If the service is not running on any node, start the service by executing the following on that node: ```bash $ sudo systemctl start mariadb ``` ## Test Local Client Connections Use [mariadb Client](https://mariadb.com/docs/server/clients-and-utilities/mariadb-client) to test the local connection to the Enterprise Server node. This action is performed **on the Spider Node and each Data Node**: ```bash $ sudo mariadb Welcome to the MariaDB monitor. Commands end with ; or \g. Your MariaDB connection id is 38 Server version: 11.4.5-3-MariaDB-Enterprise MariaDB Enterprise Server Copyright (c) 2000, 2018, Oracle, MariaDB Corporation Ab and others. Type 'help;' or '\h' for help. Type '\c' to clear the current input statement. MariaDB [(none)]> ``` The `sudo` command is used here to connect to the Enterprise Server node using the `root@localhost` user account, which authenticates using the `unix_socket` authentication plugin. Other user accounts can be used by specifying the `--user` and `--password` command-line options. ## Test Data Node Client Connection Use [mariadb Client](https://mariadb.com/docs/server/clients-and-utilities/mariadb-client) to test a client connection to the Data Node from the Spider Node using the Spider user. This action is performed **on the Spider Node**: ```bash $ mariadb \ --host 192.0.2.2 \ --user spider_user \ --password Welcome to the MariaDB monitor. Commands end with ; or \g. Your MariaDB connection id is 38 Server version: 11.4.5-3-MariaDB-Enterprise MariaDB Enterprise Server Copyright (c) 2000, 2018, Oracle, MariaDB Corporation Ab and others. Type 'help;' or '\h' for help. Type '\c' to clear the current input statement. MariaDB [(none)]> ``` The host and port of the Data Node can be provided using the `--host` and `--port` command-line options. The credentials for the Spider user can be provided using the `--user` and `--password` command-line options. If the Spider user is unable to connect to the Data Node from the Spider Node, check the password for the Spider user account on the Data Node. For additional information, see "[Create Spider User](https://mariadb.com/docs/server/architecture/topologies/step-2-configure-spider-node-and-data-nodes#create-spider-user)". ## Test Spider Storage Engine Plugin Query the `information_schema.PLUGINS` table to confirm that the Enterprise Spider storage engine is loaded. This action is performed **on the Spider Node**. Execute the following query: ```sql SELECT PLUGIN_NAME, PLUGIN_STATUS FROM information_schema.PLUGINS WHERE PLUGIN_LIBRARY LIKE 'ha_spider%'; +--------------------------+---------------+ | PLUGIN_NAME | PLUGIN_STATUS | +--------------------------+---------------+ | SPIDER | ACTIVE | | SPIDER_ALLOC_MEM | ACTIVE | | SPIDER_WRAPPER_PROTOCOLS | ACTIVE | +--------------------------+---------------+ ``` The `PLUGIN_STATUS` column for each Spider-related plugin should contain `ACTIVE`. For additional information, see "[Load the Spider Plugin](https://mariadb.com/docs/server/architecture/topologies/step-1-install-enterprise-spider#load-the-spider-plugin)". ## Test Write Operations Write to the Spider Table using an [INSERT](https://mariadb.com/docs/server/reference/sql-statements/data-manipulation/inserting-loading-data/insert) statement to test write operations. This action is performed **on the Spider Node**. Execute the following query: ```sql INSERT INTO spider_hq_sales.invoices (branch_id, invoice_id, customer_id, invoice_date, invoice_total, payment_method) VALUES (1, 4, 1, '2021-03-10 12:45:10', 3045.73, 'CREDIT_CARD'); ``` ## Test Read Operations Read from the Spider Table using a [SELECT](https://mariadb.com/docs/server/reference/sql-statements/data-manipulation/selecting-data/select) statement to test read operations. This action is performed **on the Spider Node**. Execute the following query: ```sql SELECT * FROM spider_sharded_sales.invoices; ``` ``` +-----------+------------+-------------+----------------------------+---------------+----------------+ | branch_id | invoice_id | customer_id | invoice_date | invoice_total | payment_method | +-----------+------------+-------------+----------------------------+---------------+----------------+ | 1 | 1 | 1 | 2020-05-10 12:35:10.000000 | 1087.23 | CREDIT_CARD | | 1 | 2 | 2 | 2020-05-10 14:17:32.000000 | 1508.57 | WIRE_TRANSFER | | 1 | 3 | 3 | 2020-05-10 14:25:16.000000 | 227.15 | CASH | | 1 | 4 | 1 | 2021-03-10 12:45:10.000000 | 3045.73 | CREDIT_CARD | | 2 | 1 | 2 | 2020-05-10 12:31:00.000000 | 1351.04 | CREDIT_CARD | | 2 | 2 | 2 | 2020-05-10 12:45:27.000000 | 162.11 | WIRE_TRANSFER | | 2 | 3 | 4 | 2020-05-10 13:11:23.000000 | 350.00 | CASH | | 3 | 1 | 5 | 2020-05-10 12:31:00.000000 | 111.50 | CREDIT_CARD | | 3 | 2 | 8 | 2020-05-10 12:45:27.000000 | 1509.23 | WIRE_TRANSFER | | 3 | 3 | 3 | 2020-05-10 13:11:23.000000 | 3301.66 | CASH | +-----------+------------+-------------+----------------------------+---------------+----------------+ ``` ## Test Sharding Use the [EXPLAIN PARTITIONS](https://mariadb.com/docs/server/reference/sql-statements/administrative-sql-statements/analyze-and-explain-statements/explain) statement with a [SELECT](https://mariadb.com/docs/server/reference/sql-statements/data-manipulation/selecting-data/select) statement to determine which shards Spider will read for the query. This action is performed **on the Spider Node**. Execute the following query: ```sql EXPLAIN PARTITIONS SELECT * FROM spider_sharded_sales.invoices WHERE customer_id = 4; ``` ``` +------+-------------+----------+--------------------------------------------------+------+---------------+------+---------+------+------+-----------------------------------+ | id | select_type | table | partitions | type | possible_keys | key | key_len | ref | rows | Extra | +------+-------------+----------+--------------------------------------------------+------+---------------+------+---------+------+------+-----------------------------------+ | 1 | SIMPLE | invoices | hq_partition,eastern_partition,western_partition | ALL | NULL | NULL | NULL | NULL | 9 | Using where with pushed condition | +------+-------------+----------+--------------------------------------------------+------+---------------+------+---------+------+------+-----------------------------------+ ``` The specific shards read by the query are listed in the `partitions` column. If partition pruning does not eliminate unnecessary shards for a query with a restrictive filter, then check the partition definitions. ## Next Step Navigation in the procedure "Deploy Spider Sharded Topology": This page was step 3 of 3. This procedure is complete. *This page is: Copyright © 2025 MariaDB. All rights reserved.* {% @marketo/form formId="4316" %}