Timeout on large DAST report

Summary

Providing a large (~70MB) report to artifacts:reports:dast causes the vulnerability report on the security tab to timeout.

Please do not mention customer information in this issue to it can remain public. Customer report: https://gitlab.zendesk.com/agent/filters/360062369834 (internal link)

Steps to reproduce

1. Produce a very large DAST report (~70MB)
2. Feed it to GitLab

gitlab-examples/security/security-reports/.gitlab-ci.yml Lines 6 to 11

6 7 8 9 10 11

dast:
  script:
    - unzip samples/gl-dast-report.json.zip
  artifacts:
    reports:
      dast: "gl-dast-report.json"

Example Project

https://gitlab.com/gitlab-examples/security/security-reports/-/pipelines/308256183/security

What is the current bug behavior?

An error is displayed: "Error fetching the vulnerability list. Please check your network connection and try again. "

What is the expected correct behavior?

The report contents is displayed.

Relevant logs and/or screenshots

Output of checks

Results of GitLab environment info

Expand for output related to GitLab environment info

(For installations with omnibus-gitlab package run and paste the output of:
`sudo gitlab-rake gitlab:env:info`)

(For installations from source run and paste the output of:
`sudo -u git -H bundle exec rake gitlab:env:info RAILS_ENV=production`)

Results of GitLab application Check

Expand for output related to the GitLab application check

(For installations with omnibus-gitlab package run and paste the output of:
sudo gitlab-rake gitlab:check SANITIZE=true)
(For installations from source run and paste the output of:
sudo -u git -H bundle exec rake gitlab:check RAILS_ENV=production SANITIZE=true)
(we will only investigate if the tests are passing)

Possible fixes

/cc @m_lussier @matt_wilson @sethgitlab