while viewing https://integration.wikimedia.org/ci/view/Default/job/beta-scap-eqiad/149900/console whilist it was in progress i get this

Request from *Redacted IP* via cp1051 cp1051, Varnish XID 136209466

Error: 503, Backend fetch failed at Fri, 07 Apr 2017 23:15:31 GMT

On contint1001:

[proxy_http:error] [pid 634] (20014) Internal error: [client 10.64.32.103:50115] AH01102: error reading status line from remote server localhost:8080, referer: https://integration.wikimedia.org/ci/view/Default/job/beta-scap-eqiad/149900/console

It is somehow rare but annoying:

zgrep -c AH01102 /var/log/apache2/integration_error.log*|sort -t . -k 3 -rn /var/log/apache2/integration_error.log.30.gz:20 /var/log/apache2/integration_error.log.29.gz:12 /var/log/apache2/integration_error.log.28.gz:10 /var/log/apache2/integration_error.log.27.gz:19 /var/log/apache2/integration_error.log.26.gz:20 /var/log/apache2/integration_error.log.25.gz:5 /var/log/apache2/integration_error.log.24.gz:3 /var/log/apache2/integration_error.log.23.gz:21 /var/log/apache2/integration_error.log.22.gz:15 /var/log/apache2/integration_error.log.21.gz:19 /var/log/apache2/integration_error.log.20.gz:28 /var/log/apache2/integration_error.log.19.gz:16 /var/log/apache2/integration_error.log.18.gz:13 /var/log/apache2/integration_error.log.17.gz:8 /var/log/apache2/integration_error.log.16.gz:27 /var/log/apache2/integration_error.log.15.gz:16 /var/log/apache2/integration_error.log.14.gz:21 /var/log/apache2/integration_error.log.13.gz:21 /var/log/apache2/integration_error.log.12.gz:9 /var/log/apache2/integration_error.log.11.gz:6 /var/log/apache2/integration_error.log.10.gz:1 /var/log/apache2/integration_error.log.9.gz:19 /var/log/apache2/integration_error.log.8.gz:18 /var/log/apache2/integration_error.log.7.gz:25 /var/log/apache2/integration_error.log.6.gz:48 /var/log/apache2/integration_error.log.5.gz:24 /var/log/apache2/integration_error.log.4.gz:3 /var/log/apache2/integration_error.log.3.gz:4 /var/log/apache2/integration_error.log.2.gz:16 /var/log/apache2/integration_error.log.1:30 /var/log/apache2/integration_error.log:0