Hello everyone,

We are evaluating various approaches for horizontal scalabilty of fulltext searching, and we thought about trying out Galera. We set up a 3-node cluster in Google Cloud Compute, and we tried loading a collection of 90k synthetic documents into a table like this one:

CREATE TABLE `documents` (

  `id` int(11) NOT NULL AUTO_INCREMENT,

  `filename` varchar(255) DEFAULT NULL,

  `text` longtext DEFAULT NULL,

  PRIMARY KEY (`id`)

) ENGINE=InnoDB AUTO_INCREMENT=282232 DEFAULT CHARSET=latin1

We followed the recommendation in the MariaDB docs of inserting everything, then creating the FULLTEXT index by running:

ALTER TABLE documents ADD FULLTEXT (text);

While this works fine with a regular single node configuration (without Galera), it is crashing in our Galera setup with a message like this:

Exception in thread "main" java.sql.SQLException: (conn=41) Index for table 'documents' is corrupt; try to repair it

        at org.mariadb.jdbc.internal.util.exceptions.ExceptionMapper.get(ExceptionMapper.java:198)

        at org.mariadb.jdbc.internal.util.exceptions.ExceptionMapper.getException(ExceptionMapper.java:110)

        at org.mariadb.jdbc.MariaDbStatement.executeExceptionEpilogue(MariaDbStatement.java:228)

        at org.mariadb.jdbc.MariaDbStatement.executeInternal(MariaDbStatement.java:334)

        at org.mariadb.jdbc.MariaDbStatement.executeUpdate(MariaDbStatement.java:520)

        at uk.ac.aston.erdf.mariadb.MariaDBIndexer.indexFiles(MariaDBIndexer.java:211)

        at uk.ac.aston.erdf.mariadb.MariaDBIndexer.runIteration(MariaDBIndexer.java:142)

        at uk.ac.aston.erdf.mariadb.MariaDBIndexer.run(MariaDBIndexer.java:117)

        at uk.ac.aston.erdf.mariadb.MariaDBIndexer.main(MariaDBIndexer.java:106)

Caused by: java.sql.SQLException: Index for table 'documents' is corrupt; try to repair it

Query is: ALTER TABLE documents ADD FULLTEXT (text);

        at org.mariadb.jdbc.internal.util.LogQueryTool.exceptionWithQuery(LogQueryTool.java:119)

        at org.mariadb.jdbc.internal.protocol.AbstractQueryProtocol.executeQuery(AbstractQueryProtocol.java:200)

        at org.mariadb.jdbc.MariaDbStatement.executeInternal(MariaDbStatement.java:328)

        ... 5 more

We have tried dropping and recreating the database, and SHOW STATUS lists the 3 nodes just fine:

MariaDB [(none)]> show status like 'wsrep_cluster%';

+--------------------------+--------------------------------------+

| Variable_name            | Value                                |

+--------------------------+--------------------------------------+

| wsrep_cluster_conf_id    | 12                                   |

| wsrep_cluster_size       | 3                                    |

| wsrep_cluster_state_uuid | 258a45dd-b9e0-11e8-bdd1-e260a7908d0f |

| wsrep_cluster_status     | Primary                              |

+--------------------------+--------------------------------------+

4 rows in set (0.001 sec)

Our Galera section is pretty bog standard: we followed most of the defaults in the Ubuntu MariaDB 10.3 packages, except for disabling bin logs (they take up too much space for our 40GB cloud VMs). Here is our [galera] section:

[galera]

# Mandatory settings

wsrep_on=ON

wsrep_provider=/usr/lib/libgalera_smm.so

wsrep_cluster_address=gcomm://mariadb-g1,mariadb-g2,mariadb-g3

binlog_format=row

default_storage_engine=InnoDB

innodb_autoinc_lock_mode=2

#

# Allow server to accept connections on all interfaces.

#

bind-address=0.0.0.0

#

# Optional setting

#wsrep_slave_threads=1

innodb_flush_log_at_trx_commit=0

Are we missing something obvious, or is InnoDB FULLTEXT not yet fully supported on Galera? Should we try Mroonga instead?

Thank you for your help,

Antonio