albatross/app/vmmd_stats.ml
2018-11-01 22:40:32 +01:00

110 lines
3.4 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
open Vmm_stats_pure
let t = ref (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 pids =
Vmm_lwt.read_wire s >>= function
| Error _ ->
Logs.err (fun m -> m "exception while reading") ;
Lwt.return pids
| Ok wire ->
match handle !t s wire with
| Error (`Msg msg) ->
Vmm_lwt.write_wire s (fst wire, `Failure msg) >>= fun _ ->
Lwt.return pids
| Ok (t', action, out) ->
t := t' ;
let pids = match action with
| `Add pid -> pid :: pids
| `Remove pid -> List.filter (fun m -> m <> pid) pids
| `Close _ -> pids
in
Vmm_lwt.write_wire s (fst wire, `Success (`String out)) >>= function
| Ok () ->
(match action with
| `Close (Some s') ->
Vmm_lwt.safe_close s' >>= fun () ->
(* read the next *)
Vmm_lwt.read_wire s >|= fun _ -> pids
| _ -> loop pids)
| Error _ ->
Logs.err (fun m -> m "error while writing") ;
Lwt.return pids
in
loop [] >>= fun vmids ->
Vmm_lwt.safe_close s >|= fun () ->
Logs.warn (fun m -> m "disconnect, dropping %d vms!" (List.length vmids)) ;
t := remove_vmids !t vmids
let rec timer interval () =
let t', outs = 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 ->
Logs.debug (fun m -> m "removing entry %a" Vmm_core.pp_id name) ;
t := remove_entry !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 ())
open Cmdliner
open Vmm_cli
let socket =
let doc = "socket to use" in
Arg.(value & opt string (Vmm_core.socket_path `Stats) & info [ "socket" ] ~doc)
let interval =
let doc = "Interval between statistics gatherings (in seconds)" in
Arg.(value & opt int 10 & info [ "interval" ] ~doc)
let cmd =
Term.(ret (const jump $ setup_log $ socket $ interval)),
Term.info "vmmd_stats" ~version:"%%VERSION_NUM%%"
let () = match Term.eval cmd with `Ok () -> exit 0 | _ -> exit 1