albatross/stats/vmm_stats_lwt.ml

107 lines
3.5 KiB
OCaml

(* (c) 2017, 2018 Hannes Mehnert, all rights reserved *)
(* the process responsible for gathering statistics (CPU + mem + network) *)
(* a shared unix domain socket between vmmd and vmm_stats is used as
communication channel, where the vmmd can issue commands:
- add pid taps
- remove pid
- statistics pid
every 10 seconds, statistics of all registered pids are recorded. `statistics`
reports last recorded stats *)
open Lwt.Infix
let t = ref (Vmm_stats.empty ())
let pp_sockaddr ppf = function
| Lwt_unix.ADDR_UNIX str -> Fmt.pf ppf "unix domain socket %s" str
| Lwt_unix.ADDR_INET (addr, port) -> Fmt.pf ppf "TCP %s:%d"
(Unix.string_of_inet_addr addr) port
let handle s addr () =
Logs.info (fun m -> m "handling stats connection %a" pp_sockaddr addr) ;
let rec loop acc =
Vmm_lwt.read_wire s >>= function
| Error (`Msg msg) -> Logs.err (fun m -> m "error while reading %s" msg) ; loop acc
| Error _ -> Logs.err (fun m -> m "exception while reading") ; Lwt.return acc
| Ok (hdr, data) ->
Logs.debug (fun m -> m "received %a" Cstruct.hexdump_pp data) ;
let t', action, out = Vmm_stats.handle !t s hdr data in
let acc = match action with
| `Add pid -> pid :: acc
| `Remove pid -> List.filter (fun m -> m <> pid) acc
| `None -> acc
in
t := t' ;
Logs.debug (fun m -> m "sent %a" Cstruct.hexdump_pp out) ;
Vmm_lwt.write_wire s out >>= function
| Ok () -> loop acc
| Error _ -> Logs.err (fun m -> m "exception while writing") ; Lwt.return acc
in
loop [] >>= fun vmids ->
Lwt.catch (fun () -> Lwt_unix.close s) (fun _ -> Lwt.return_unit) >|= fun () ->
Logs.warn (fun m -> m "disconnect, dropping %d vms!" (List.length vmids)) ;
let t' = Vmm_stats.remove_vmids !t vmids in
t := t'
let rec timer interval () =
let t', outs = Vmm_stats.tick !t in
t := t' ;
Lwt_list.iter_p (fun (s, name, stat) ->
Vmm_lwt.write_wire s stat >>= function
| Ok () -> Lwt.return_unit
| Error `Exception ->
t := Vmm_stats.remove_socket !t name ;
Vmm_lwt.safe_close s)
outs >>= fun () ->
Lwt_unix.sleep interval >>= fun () ->
timer interval ()
let jump _ file interval =
Sys.(set_signal sigpipe Signal_ignore) ;
let interval = Duration.(to_f (of_sec interval)) in
Lwt_main.run
((Lwt_unix.file_exists file >>= function
| true -> Lwt_unix.unlink file
| false -> Lwt.return_unit) >>= fun () ->
let s = Lwt_unix.(socket PF_UNIX SOCK_STREAM 0) in
Lwt_unix.(bind s (ADDR_UNIX file)) >>= fun () ->
Lwt_unix.listen s 1 ;
Lwt.async (timer interval) ;
let rec loop () =
Lwt_unix.accept s >>= fun (cs, addr) ->
Lwt.async (handle cs addr) ;
loop ()
in
loop ())
let setup_log style_renderer level =
Fmt_tty.setup_std_outputs ?style_renderer ();
Logs.set_level level;
Logs.set_reporter (Logs_fmt.reporter ~dst:Format.std_formatter ())
open Cmdliner
let setup_log =
Term.(const setup_log
$ Fmt_cli.style_renderer ()
$ Logs_cli.level ())
let socket =
let doc = "Socket to listen on" in
let sock = Vmm_core.socket_path `Stats in
Arg.(value & opt string sock & info [ "s" ; "socket" ] ~doc)
let interval =
let doc = "Interval between statistics gatherings (in seconds)" in
Arg.(value & opt int 10 & info [ "internval" ] ~doc)
let cmd =
Term.(ret (const jump $ setup_log $ socket $ interval)),
Term.info "vmm_stats" ~version:"%%VERSION_NUM%%"
let () = match Term.eval cmd with `Ok () -> exit 0 | _ -> exit 1