Re: Aurora PostgreSQL Support

Hi Goti,

I would suggest generating a report using the aws schema migration tool to
see what ddl might need to be changed or rewritten).

Some Aurora configuration is determined by instance size such as number of
max connections. The rest will be in the cluster and instance parameter
groups (which are tied to Postgres compatibility mode).

I would absolutely recommend creating cluster and instance parameter groups
first and with automation. This costs nothing and will help you determine
what parameters you might be interested in changing.

As to other comments in this thread about migrating a distributed columnar
store with huge page sizes (aka Redshift) to Aurora Postgres... I can only
speculate wrong tool for the wrong job. Aurora is optimized for OLTP type
workloads. So, Aurora would excel for a write heavy workload such as
collecting IoT events but I would expect it to underperform Redshift for
analytics at scale.

There seem to be some Aurora Postgres haters out there, but, I'm not one at
all. I have been using and administrating Postgres for a number of years
and have few complaints about Postgres or Postgres Aurora. Easy to
automate cluster build with Terraform to include configuration, and some
level of monitoring on infrastructure (GruntWorks modules are an ok
starting point).

Some additional observability and monitoring is needed after provisioning.

The only issues I have ever had with Aurora Postgres were:
1) Failed to upgrade major version. Fixed by adding new nodes to cluster,
removing old nodes and running upgrade.

2) Configuration drift in Cluster Parameter group where old default value
impacted some client connections default_tablespace if memory serves). Fix,
set value to blank as this is valid default for Postgres.

All other issues were run of the mill issues where I was quickly able to
help developers out. Hope this helps.

Best regards,

Dan Smith

On Fri, Feb 19, 2021, 12:52 Avinash Kumar <avinash(dot)vallarapu(at)gmail(dot)com>
wrote:

> If you are ready for some Bugs that you don't find in Community
> PostgreSQL, then you may feel free to think of it.
>
> One of the latest unfixed Aurora PostgreSQL 12 bugs is reproduced and
> documented in this blog post.
>
>
> https://www.migops.com/blog/2021/02/15/a-bug-on-aurora-postgresql-12-causes-autovacuum-to-hang-forever/
>
>
>
>
> On Fri, Feb 19, 2021 at 8:34 AM dbatoCloud Solution <
> dbatocloud17(at)gmail(dot)com> wrote:
>
>> Dear Rakesh
>>
>> Prince is correct.
>>
>> @Rakesh T # The below parameter value cannot be changed in aurora
>> database. I tried to change in parameter group level but there is no option
>> even I checked with AWS
>> It is not possible to change this setting. In our environment is Dataware
>> where we are having huge DML,Select & I/O happening I asked AWS to
>> support/give Dataware house best practice
>> so that I can follow but no support from AWS.
>>
>> min_wal_size
>> max_wal_size
>> effective_io_concurrency
>> checkpoint_completion_target
>>
>>
>>
>> It can be done in the community version.
>>
>>
>> My suggestion better to go-ahead with RDS-PostgreSQL, or EC2-> PostgreSQL
>> but not Aurora postgreSQL.
>>
>>
>>
>>
>>
>> Thanks & Best Wishes,
>>
>> Ashok
>>
>>
>>
>>
>> ---------------------------------------------------------------------------------------------------------------------
>>
>> Ashokkumar Mani *(OCP12c/11g/10g/9i, AWS SAA, M103)*
>>
>> *Dubai** , UAE* *| BLR , INDIA*
>>
>> M: *+971 54 723 0075 *| *+91 90086 70302 | *WApp :* +91 81975 99922*
>>
>> W: https://dbatocloudsolution.blogspot.in/
>> <http://dbatocloudsolution.blogspot.in/> | E: dbatocloud17(at)gmail(dot)com
>>
>>
>> On Thu, Feb 18, 2021 at 11:47 AM Prince Pathria <
>> prince(dot)pathria(at)goevive(dot)com> wrote:
>>
>>> One of the issues I faced in the past is limited(not expandable) tmp
>>> storage. If your query is huge, it may fail.
>>> AWS docs don't tell such things explicitly so have intensive testing on
>>> Aurora before planning to migrate.
>>> RDS seems to be a safe choice.
>>>
>>> Quoting from the doc - "Each Aurora DB instance contains a limited
>>> amount of local storage that is determined by the DB instance class.
>>> Typically, the amount of local storage is twice the amount of memory on the
>>> DB instance."
>>> ref.
>>> https://aws.amazon.com/premiumsupport/knowledge-center/postgresql-aurora-storage-issue/
>>>
>>>
>>> Happy to help :)
>>> Prince Pathria Cloud Engineer II| Certified Kubernetes Administrator |
>>> AWS Certified Solutions Architect Evive +91 9478670472 goevive.com
>>>
>>>
>>> On Thu, Feb 18, 2021 at 11:33 AM dbatoCloud Solution <
>>> dbatocloud17(at)gmail(dot)com> wrote:
>>>
>>>> Hi Rakesh
>>>> I would suggest to go for EC2 then install PostgreSQL then use it. I am
>>>> facing lot of problems in Aurora PostgreSQL
>>>>
>>>> Thanks
>>>> Ashok
>>>>
>>>> On Thu, Feb 18, 2021, 10:04 Rakesh T <aryan(dot)goti(at)gmail(dot)com> wrote:
>>>>
>>>>> Hi Listeres,
>>>>>
>>>>> I am looking for suggestions from people who have experience with
>>>>> Aurora PostgreSQL.
>>>>>
>>>>> I work as a database admin in my company. We are migrating some of our
>>>>> Oracle databases to Aurora PostgreSQL. Since this falls under the RDS
>>>>> category I understand that the majority of the admin work will be managed
>>>>> by AWS team itself. But from a business unit perspective, they are looking
>>>>> for support from my team with regards to general BU work and performance
>>>>> and tuning. Can someone shed some light on possible areas which we can
>>>>> support in the RDS Aurora PostgreSQL world?
>>>>>
>>>>> Thanks in Advance!
>>>>>
>>>>> Thanks,
>>>>> Goti
>>>>>
>>>>
>
> --
> Regards,
> Avinash Vallarapu
> MigOps Inc.
> CEO.
>