SQLAlchemy collector requires database with JSON data type support - undocumented

[Radoslaw Smigielski]

When databases older than listed below are used as collector backend:
1. MariaDB 10.2
2. MySQL 5.7.8

service fails to start with error like below:

> ProgrammingError: (pymysql.err.ProgrammingError) (1064, u"You have an error in your SQL syntax; check the manual that corresponds to your MariaDB server version for the right syntax to use near 'JSON, \\n\\tPRIMARY KEY (id)\\n)' at line 11")

We probably should document that for SQLAlchemy collector requires specific versions of databases.

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.opendev.org/654114

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.opendev.org/654114
Committed: https://git.openstack.org/cgit/openstack/osprofiler/commit/?id=9847b8984a0e8ac9c325962431c08d7dddff13bc
Submitter: Zuul
Branch: master

commit 9847b8984a0e8ac9c325962431c08d7dddff13bc
Author: Radoslaw Smigielski <email address hidden>
Date: Sun Apr 21 06:22:43 2019 +0200

    Minimum versions of databases with JSON data type support

    SQLAlchemy collector requires database JSON data type support
    which is fairly new feature and missing in versions older than:

        - MariaDB 10.2
        - MySQL 5.7.8

    Let's document that SQLAlchemy collector requirement.

    Change-Id: Ifb379a40d90d252d56d4f830e75bbfa08bf66a01
    Closes-Bug: #1825693

[OpenStack Infra (hudson-openstack)]

This issue was fixed in the openstack/osprofiler 2.7.0 release.