Can't import repository due to "Received a GOAWAY with error code ENHANCE_YOUR_CALM"

I’m trying to import bare repositories into my self hosted gitlab instance.

gitlab-rake gitlab:import:repos works fine for my first, small (~50MB) repository, but the second one (~10GB) throws an error after 30mins of processing:

E0507 11:39:44.068016828 3959] Received a GOAWAY with error code ENHANCE_YOUR_CALM and debug data equal to “too_many_pings”

  • Failed to move repo: 14:Socket closed

I tried to increase some limit variables in admin area, but nothing helped.
Gitlab is hosted inside docker container.