On 10/8/13 18:22 , Alex Wilson wrote: > Hi all, > > Currently in sysevent, the maximum number of subscribers to a channel is set > to EVCH_MAX_SUBSCRIPTIONS, which is unchangeable at run time (except via mdb > fiddling with a channel after it's been created). The value in illumos at the > moment is 32, which seems very low, especially for system-wide channels like > the zone status one. I was wondering if anybody knows of adverse impacts > there might be by increasing this -- to 256 or 512 or so. Will this cause > serious problems anywhere (beyond making posting events to channels that > actually have that many subscriptions a bit slower)? > > For the background about why I'm asking this: I'm using Project FIFO's > chunter on SmartOS, and chunter uses a library called libzdoor that Joyent > provide for zone <-> global zone communication (specifically, it lets chunter > decide centrally to approve/deny ssh logins with a public key). Libzdoor > makes a subscription (indirectly) to the com.sun:zones:status channel for > every zone you want to communicate with, so if I have >32 zones on one host, > it starts dying with ENOMEM (the return value when you have exceeded the max > subscribers limit) and even zoneadm and friends start playing up.
In general, we could increase it, but having the global zone have one listener on the sysevent per zone is a bad idea and definitely doesn't scale. Increasing the number doesn't really solve the core problem that you actually have. It's easy to imagine systems where you have more zones than whatever new number you pick. What needs to be fixed is the fact that it indirectly has one sysevent subscription per zone on the box. Robert ------------------------------------------- illumos-discuss Archives: https://www.listbox.com/member/archive/182180/=now RSS Feed: https://www.listbox.com/member/archive/rss/182180/21175430-2e6923be Modify Your Subscription: https://www.listbox.com/member/?member_id=21175430&id_secret=21175430-6a77cda4 Powered by Listbox: http://www.listbox.com
