I've spent about a week trying to build a stable instance of OQGRAPH for use by a webserver.
Finding that almost every-other external query results in InnoDB: Assertion failure. But no issues when using the CLI on localhost or a remote_host.
Note: The first query normally works, and subsequent queries fail. I've been using a stored procedure that normally restarts MariaDB, so every-other-query works.
This is a clean build, minimal CentOS, EPEL, & MariaDB from the repo. I've tried multiple MariaDB (default config) builds, even reverted to CentOS 6.3 to see if that would make a difference. I originally suspected the problem might with PHP, but no difference between mysql ' mysqli. Then I found the issue was reproducible from bash.
Attached you will find the syslog message, stored procedure, plus the DB schema and quick setup I have been working with. If you have any questions, please let me know.