Yum times out when pointing to a group repository

Hi, I have setup two proxied repos for CentOS AppStream and CentOS BaseOS. Both of these work fine individually. When I create a Yum Group repo that contains these two repos my client VM times out when I run yum makecache. There are only two cached RPM’s (tar and nano)

[root@VM1 simon]# yum makecache
Nexus CentOS All Repos                                                                                                                                                                          0.0  B/s |   0  B     02:00
Errors during downloading metadata for repository 'nexus-centos-all':
  - Curl error (28): Timeout was reached for [Operation too slow. Less than 1000 bytes/sec transferred the last 30 seconds]
Error: Failed to download metadata for repo 'nexus-centos-all': Cannot download repomd.xml: Cannot download repodata/repomd.xml: All mirrors were tried

My nexus VM has 4 cores, 8GB memory and is using SSD drives. It’s running on a hetzner cloud server.
Disk speed on the nexus VM is not a problem

dd if=/dev/zero of=/tmp/test1.img bs=1G count=1 oflag=dsync
1+0 records in
1+0 records out
1073741824 bytes (1.1 GB, 1.0 GiB) copied, 0.92498 s, 1.2 GB/s

The issue is probably caused by the yum repodata merge in the group where you have several large repos (with many packages stored). During this period repomd.xml is not available. Nexus even doesn’t try to cache previous version until the rebuild.

We suffer from the same issue having probably the same setup (few default CentOS repos in a group). Support told us that we simply try to group “too large repositories” so that means Nexus is not capable to process such load.

The only suggestion I have for you (and that is what we have done) is to switch to separate proxies for each specific CentOS repo.

We have a fix included in the upcoming 3.46 release which may address this problem. I’m afraid I don’t have a public ticket for it.