Edit pages with a lot of JIRA issues macros using "total issue count" takes a long time

Confluence takes a long time to open the editor when editing pages with lots of JIRA issues macros using the total issue count.

The CPU also spikes for a brief time during the editor loading time.

How to replicate

• JIRA 8.13.5
• Confluence 7.13

1) Create a project on JIRA and add a few issues (2 for example).
2) Set the application links between Confluence and JIRA
3) Create a new page in Confluence and add a JIRA issue macro using the project created on number 1 above.
4) On the JIRA macro display options, select the total issue count display.
5) Save the page.

Editing the page with a single issue works fine. However, as we add more and more JIRA macros to the page with the "total issue count", the editor becomes slower each time.

Disabling the collaborative editor does not help.
The issue happens with simple and complex JIRA macro filters.

Observed results

Editing the same page with more JIRA macros produced the following results:

1) Page with 10 JIRA issues = 5 seconds
2) Page with 50 JIRA issues = 8 seconds
3) Page with 100 JIRA issues = 12.6 seconds
4) Page with 250 JIRA issues = 19.5 seconds

As the number of issues on a page increases, the time to edit also continues increasing.

This HAR shows the behavior when loading the editor:

Expected behavior

Confluence should open the page editor faster.

Workaround

From Confluence 7.8.1 onward the dark features confluence.extra.jira.edit.ignore.count can be used to reduce the impact of this issue. With this dark feature enabled, Confluence will not attempt to load issue counts, and instead will display "x" in edit mode instead.

Notes

During tests, it was observed that changing the JIRA macro display mode to table renders the edit page really fast (under 5 seconds), even when using 250 JIRA macros on the same page.

The behavior seems tied to the total issue count display mode.