Fix summariser time CpuCount warnings for cloud accounting

[gregcorbett]

The warnings are caused by CloudRecords with a NULL CpuCount forming CloudSummaries with a NULL CpuCount, which causes the warning because CpuCount is now part of the CloudSummaries primary key (following a bug fix in 1.6.1).

I have made a change to cloud.py to prevent new CloudRecords being loaded with a NULL CpuCount, opting for zero as the replacement, so CloudRecords without a CpuCount are as separate as possible from those that do.

I also added test cases to try and highlight what was changing and to show that everything still seems to work.

Manual Testing

Tested by loading the below message repeatedly into a Cloud database (10.1.20-MariaDB) on a SL7 VM

BenchmarkType: HEPSPEC06
Status: completed
SiteName: Test Site
MachineName: Test Machine
ImageId: Test Image ID
LocalUserId: Test Local User ID
FQAN: NULL
LocalGroupId: Test Local Group ID
VMUUID: datetime.now()
CloudType: caso/0.3.4 (OpenStack)
GlobalUserName: Test User
CloudComputeService: Test Service

under 1.6.1, when loading that message we pass NULL to CpuCount, rather than relying on implicit type correction that's not supported out of the box in newer mysql/mariadb. Woo!

+----------------------------+-----------+----------+
| VMUUID                     | SiteName  | CpuCount |
+----------------------------+-----------+----------+
| 2018-03-22 16:24:01.535679 | Test Site |     NULL |
+----------------------------+-----------+----------+

This causes the summariser warnings, because CpuCount is in the primary key and hence NOT NULL in the CloudSummaries table.

Query OK, 1 row affected, 3 warnings (0.02 sec)

MariaDB [cloud_dev]> show warnings;
+---------+------+----------------------------------+
| Level   | Code | Message                          |
+---------+------+----------------------------------+
| Warning | 1048 | Column 'Month' cannot be null    |
| Warning | 1048 | Column 'Year' cannot be null     |
| Warning | 1048 | Column 'CpuCount' cannot be null |
+---------+------+----------------------------------+

We get away with it because of the implict type correction of NULL to 0 that's not supported out of the box in newer mysql/mariadb. Boo!

+---------------------+-----------+----------+
| UpdateTime          | SiteName  | CpuCount |
+---------------------+-----------+----------+
| 2018-03-22 16:25:54 | Test Site |        0 |
+---------------------+-----------+----------+

To fix existing data, applying the update script

mysql -u root cloud_dev < scripts/update-1.6.1-next_version.sql

+----------------------------+-----------+----------+
| VMUUID                     | SiteName  | CpuCount |
+----------------------------+-----------+----------+
| 2018-03-22 16:24:01.535679 | Test Site |        0 |
+----------------------------+-----------+----------+

MariaDB [cloud_dev]> Call SummariseVMs();
Query OK, 2 rows affected, 2 warnings (0.02 sec)

MariaDB [cloud_dev]> show warnings;
+---------+------+-------------------------------+
| Level   | Code | Message                       |
+---------+------+-------------------------------+
| Warning | 1048 | Column 'Month' cannot be null |
| Warning | 1048 | Column 'Year' cannot be null  |
+---------+------+-------------------------------+

and no stale summaries :)

+---------------------+-----------+----------+
| UpdateTime          | SiteName  | CpuCount |
+---------------------+-----------+----------+
| 2018-03-22 16:28:03 | Test Site |        0 |
+---------------------+-----------+----------+

The changes to the cloud.py mean newly loaded records without a CpuCount get a CpuCount of 0.

+----------------------------+-----------+----------+
| VMUUID                     | SiteName  | CpuCount |
+----------------------------+-----------+----------+
| 2018-03-22 16:24:01.535679 | Test Site |        0 |
| 2018-03-22 16:30:20.062425 | Test Site |        0 |
+----------------------------+-----------+----------+

[tofu-rocketry]

Looks good. Just a couple of things in the comments.

[tofu-rocketry]

Little ambiguous. You mean problems at summarising time, right?

[gregcorbett]

Yes, change made

[tofu-rocketry]

Missing "load"?

[gregcorbett]

Yes, change made

[gregcorbett]

Changes made

[tofu-rocketry]

I've split the comment fix commit, squashed each bit into the relevant commit, and rebased.