albatross/stats/vmm_stats_lwt.ml

82 lines
2.6 KiB
OCaml

(* (c) 2017 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 5 minutes, 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 () =
Vmm_lwt.read_exactly s >>= function
| Error (`Msg msg) -> Logs.err (fun m -> m "error while reading %s" msg) ; loop ()
| Error _ -> Logs.err (fun m -> m "exception while reading") ; Lwt.return_unit
| Ok (hdr, data) ->
Logs.debug (fun m -> m "received %a" Cstruct.hexdump_pp (Cstruct.of_string data)) ;
let t', out = Vmm_stats.handle !t hdr data in
t := t' ;
Logs.debug (fun m -> m "sent %a" Cstruct.hexdump_pp (Cstruct.of_string out)) ;
Vmm_lwt.write_raw s out >>= function
| Ok () -> loop ()
| Error _ -> Logs.err (fun m -> m "exception while writing") ; Lwt.return_unit
in
loop () >>= fun () ->
Lwt.catch (fun () -> Lwt_unix.close s) (fun _ -> Lwt.return_unit)
let rec timer () =
t := Vmm_stats.tick !t ;
Lwt_unix.sleep Duration.(to_f (of_sec 15)) >>= fun () ->
timer ()
let jump _ file =
Sys.(set_signal sigpipe Signal_ignore) ;
Lwt_main.run
(let s = Lwt_unix.(socket PF_UNIX SOCK_STREAM 0) in
Lwt_unix.(Versioned.bind_2 s (ADDR_UNIX file)) >>= fun () ->
Lwt_unix.listen s 1 ;
Lwt.async timer ;
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 onto" in
Arg.(value & pos 0 string "" & info [] ~doc)
let cmd =
Term.(ret (const jump $ setup_log $ socket)),
Term.info "vmm_stats" ~version:"%%VERSION_NUM%%"
let () = match Term.eval cmd with `Ok () -> exit 0 | _ -> exit 1