CBA is shifting to cloud versions of Atlassian software

The Commonwealth Bank is moving to cloud-based versions of Atlassian software it uses, migrating 25,000 Jira users to Atlassian Cloud in November last year, with a similar migration underway for its Confluence environment.

Chief engineer Helen Lau told the recent Atlassian Team ‘23 conference that the bank had steadily grown its use of on-premises versions of Jira and Confluence since 2013.

It moved from 1700 Jira users in 2017 to 11,000 in 2019, 13,000 in 2020 and 16,000 in 2021, a period that coincided with the bank’s embrace of agile and DevOps principles and tooling to build and deploy new features faster.

But Lau said that by the end of 2021, the bank had “started to observe some performance issues with the on-prem instance of Jira”.

“That's when we start to ask ourselves, ‘Should we continue our on-prem journey or should we look at another alternative which is Atlassian Cloud?” she said.

“We decided on the latter, [and] in 2022 we have successfully migrated 25000 Jira users from on-prem to Atlassian Cloud.”

Lau said the bank would have gone down the cloud-based path for Jira back in 2017, except that service did not meet data residency requirements necessary for regulatory approval.

“In 2017, Atlassian Cloud was not an option for CBA because that was not hosted within Australia,” Lau said.

“As part of the [2022] migration project, we collaborated with Atlassian engineers [and] we came up with the feature of pinning our cloud instance to an [Atlassian] Australian data centre only, and that is meeting our compliance requirement from a regulatory point of view.

“We also reviewed all [Jira] plugin hosting one by one to ensure that they are either hosted in an Australian data center or a cloud that we have approved.”

Lau said that CBA and Atlassian engineers also worked closely to enable single sign-on to the cloud-based Jira via “multiple identity providers”.

“The bank has many subsidiaries and businesses, so one of the requirements we have is the ability to integrate with multi-cloud instances and authenticate with multiple identity providers,” Lau said.

“That was one of the Atlassian roadmap items that was not delivered at the time of when we embarked the migration journey.

“With the support of Atlassian’s partnership and collaboration, Atlassian has prioritised that multi-IdP support for CBA … pointing [Jira] to multiple identity providers for us.”

Lau said a meticulous migration and cutover from on-premises to cloud-based Jira was planned out for late 2022.

It needed to take into account a range of potential challenges, from how data could be securely migrated, to team and resource interdependencies and technical differences between the on-premises and cloud versions.

“The Data Center instance of Jira and Atlassian Cloud is actually very different - the data model and how it is set up - so mapping our on-prem environment with the cloud instance and the migration path was quite an effort for us,” Lau said.

A 60-hour migration window was planned, though Jira was available in read-only mode for much of it.

“That was not a palatable communication across operations where we tell 25,000 Jira users that they cannot use their instance for 60 hours,” she said.

“The way we overcame that is we actually turned our on-prem data centre to read-only mode on Thursday afternoon and we migrated over the night of Thursday and Friday, so that we minimised impact to our business operations to only one business day. 

“Over the weekend of the cutover window, we migrated all the data to the cloud and on the Monday morning at 7am, we flipped the switch and every single user was using Atlassian Cloud.”

The project team, of CBA and Atlassian engineers, was co-located onsite at the bank for the pre-migration, migration and hypercare period following the switch.

Lau said there had been no priority one, two or three incidents since the switch, nor unplanned outages.

The next step, she said, is to run a similar migration for Confluence, Atlassian’s collaboration tool, shifting 30,000 users from an on-premises version to a cloud-based version.

This would also “unleash the full potential of the platform” within the bank, Lau said.