WordPress plugin All-In-One Event Calendar outlinks cause crashes with OSError: [Errno 24] Too many open files

[JustAnotherArchivist]

Several ArchiveBot jobs have crashed recently with OSError: [Errno 24] Too many open files in the middle of going through All-In-One Event Calendar outlinks to Google and Outlook calendars (^https?://www\.google\.com/calendar/render\? and ^https?://outlook\.(office|live)\.com/owa\?).

Examples: 44yn9z5lv0i3m952so24dhzp1 ectefgx5qwyzn2lc9us8r3l2y 9c685inp9pj8alvs5qv7dh7r4 4gum0qpj1ptrdgllzn5uu7t10 220qoi02tpk1ouoqvzdi6n7t3 ceevjyjh5ihn9psjzjmv9ei5p 6nu0lcio4webs3bc69wvumkez

On looking at the process with lsof after the crash, there are hundreds upon hundreds of TCP and TCPv6 sockets without details. They don't appear in netstat. This seems to suggest that sockets aren't getting closed properly in some cases. Both Google and Outlook involve several redirects, which may be related. The crashes only started recently though, the first occurrences were in July. So something must've changed on their side, too.