2017-04-06 11:24 AEST by Arthur Barrett - audit support for spanner (cloud based distributed database).

There are lots of alternatives here...
- Amazon’s Aurora (MySQL compatible?)
- Microsoft Azure SQL Server
- Amazon RDS (Relational Database System)
- Alibaba Cloud ApsaraDB for RDS (Relational Database System)  MySQL, SQL Server and PostgreSQL
https://intl.aliyun.com/product/apsaradb-for-rds

Using a cloud DB that is 'compatible' with MySQL is probably sensible, but also key is the price and security.  
If a customer is going to choose to store the AuditDB in the could - why are they going to do that?
- because it's reliable / redundant / offsite-independent?
- cost
- available query tools
- other???

Google's spanner pricing:
at $0.90 per node per hour and $0.30 per GB 

I'm thinking nodes are like instances or regions... If the node is up 24x7x365 then it's about $8000 per year, 
plus the data costs and internet egress costs (potentially - depending on location):
https://cloud.google.com/spanner/pricing

The node price per hour is not variable upon your usage - if the node is a part of your 'project' you are paying 
for it - even if there are zero cycles/reads/writes.

Compare that to a small (rds.mysql.t1.small) mysql instance on AsparaDB (Alibaba) at US$29 per month (or 
small postgres rds.pg.t1.small for $33 per month) - the google spanner is looking very expensive...  But whilst 
AsparaDB is available in many regions (Singapore, Hong Kong, US West, US East etc.) it says "When you 
chose the multi-zone deployment option, ApsaraDB for RDS automatically replicates your data across 
different zones and enhances the availability and reliability of your production workloads." which suggests 
you could have a 2 zone deployment of postgres for less than $1000 pa: 
https://intl.aliyun.com/product/apsaradb-for-rds#RdsStorageNetTableTrans_SG

For a multi-zone reserved 1yr (db.t2.small) deployment on Amazon you are looking at similar prices $424 US 
East) and $361 (Sydney):
https://aws.amazon.com/rds/pricing/


Also see bug 6707 - enh: audit support for mariadb (non-oracle mysql)