On Wed, Feb 25, 2026 at 04:22:04PM +0000, Egor Shestakov wrote: > Hi Willy! > > On Wed, Feb 25, 2026 at 08:54:08AM +0100, Willy Tarreau wrote: > > That's a good point, however it will not help the users locate the right > > tunable either. I think it can be useful to print actconn, which is the > > number of active front connections and can definitely give a hint about > > a limit that might have been encountered (e.g. if you see 125000, it > > instantly rules out any lower threshold). You can log it as "actconn=" > > since it's already mentioned in the doc about log formats. > > > > Do you mean print the actconn in both cases? I understand it for ENFILE, > because the actconn, which is almost at the system limits, eliminates all > doubts. I suppose that ENOMEM is mostly caused by a large number of opened > FDs and printing this number can be useful, but I feel some lack of > coherency between actconn and ENOMEM.
Yes it can be useful because it gives a hint about the possible cause for ENOMEM. We've seen allocation error cases in environments trying to boot with super high limits for example. In the event the limit remains high but still allows to boot, it could be conceivable that an allocation failure happens during a DoS. In that case you'd probably be happy to see with ENOMEM that you already had 12 million connections. Willy
