Megatest

;; 
;;     You should have received a copy of the GNU General Public License
;;     along with Megatest.  If not, see <http://www.gnu.org/licenses/>.
;;

(declare (unit server))

(declare (uses commonmod))
(declare (uses configfmod))
(declare (uses common))
(declare (uses db))
(declare (uses debugprint))
(declare (uses common))
(declare (uses db))
(declare (uses commonmod))
(declare (uses configfmod))
(declare (uses tasks)) ;; tasks are where stuff is maintained about what is running.
;; (declare (uses synchash))
(declare (uses rmtmod))
;;(declare (uses rpc-transport))
(declare (uses launch))
;; (declare (uses daemon))
(declare (uses mtargs))

(use (srfi 18) extras s11n)
(use srfi-1 posix regex regex-case srfi-69 hostinfo md5 message-digest)
(use directory-utils posix-extras matchable utils)
(use spiffy uri-common intarweb http-client spiffy-request-vars)

(import commonmod
	configfmod
	debugprint
	(prefix mtargs args:))

(include "common_records.scm")
(include "db_records.scm")

(define (server:make-server-url hostport)
  (if (not hostport)
      #f
      (conc "http://" (car hostport) ":" (cadr hostport))))

(define (db:kill-servers)
(define  *server-loop-heart-beat* (current-seconds))

  (let* ((tl (launch:setup)) ;; need this to initialize *toppath*
;;======================================================================
;; P K T S   S T U F F 
;;======================================================================

        (servdir (conc *toppath* "/.servinfo"))
;; ???

        (servfiles (glob (conc servdir "/*:*.db")))
;;======================================================================
;; P K T S   S T U F F 
;;======================================================================

        (fmtstr  "~10a~22a~10a~25a~25a~8a\n")
;; ???

        (dbfiles (append (glob (conc *toppath* "/.mtdb/main.db")) (glob (conc *toppath* "/.mtdb/?.db"))(glob (conc *toppath* "/.mtdb/??.db"))))
;;======================================================================
;; S E R V E R
;;======================================================================

;; Call this to start the actual server
;;

;;======================================================================
;; S E R V E R   U T I L I T I E S 
;;======================================================================

;; Get the transport
(define (server:get-transport)
  (if *transport-type*
      *transport-type*
      (let ((ttype (string->symbol
		    (or (args:get-arg "-transport")
			(configf:lookup *configdat* "server" "transport")
			"rpc"))))
	(set! *transport-type* ttype)
	ttype)))
	    
;; Generate a unique signature for this server
(define (server:mk-signature)
  (message-digest-string (md5-primitive) 
			 (with-output-to-string
			   (lambda ()
			     (write (list (current-directory)
                                          (current-process-id)
					  (argv)))))))

(define (server:get-client-signature)
  (if *my-client-signature* *my-client-signature*
      (let ((sig (server:mk-signature))) ;; clients re-use the server:mk-signature logic
        (set! *my-client-signature* sig)
        *my-client-signature*)))

(define (server:get-server-id)
  (if *server-id* *server-id*
      (let ((sig (server:mk-signature))) ;; clients re-use the server:mk-signature logic
        (set! *server-id* sig)
        *server-id*)))

;; ;; When using zmq this would send the message back (two step process)
;; ;; with spiffy or rpc this simply returns the return data to be returned
;; ;; 
;; (define (server:reply return-addr query-sig success/fail result)
;;   (debug:print-info 11 *default-log-port* "server:reply return-addr=" return-addr ", result=" result)
;;   ;; (send-message pubsock target send-more: #t)
;;   ;; (send-message pubsock 
;;   (case (server:get-transport)
;;     ((rpc)  (db:obj->string (vector success/fail query-sig result)))
;;     ((http) (db:obj->string (vector success/fail query-sig result)))
;;     ((fs)   result)
;;     (else 
;;      (debug:print-error 0 *default-log-port* "unrecognised transport type: " *transport-type*)
;;      result)))

;; Given an area path,  start a server process    ### NOTE ### > file 2>&1 
;; if the target-host is set 
;; try running on that host
;;   incidental: rotate logs in logs/ dir.
;;
(define  (server:run areapath) ;; areapath is *toppath* for a given testsuite area
  (let* ((testsuite   (common:get-testsuite-name))
	 (logfile     (conc areapath "/logs/server.log")) ;; -" curr-pid "-" target-host ".log"))
	 (profile-mode (or (configf:lookup *configdat* "misc" "profilesw")
			   ""))
	 (cmdln (conc (common:get-megatest-exe)
		      " -server - ";; (or target-host "-")
		      (if (equal? (configf:lookup *configdat* "server" "daemonize") "yes")
			  " -daemonize "
			  "")
		      ;; " -log " logfile
		      " -m testsuite:" testsuite
		      " " profile-mode
		      )) ;; (conc " >> " logfile " 2>&1 &")))))
	 (log-rotate  (make-thread common:rotate-logs  "server run, rotate logs thread")) ;; why are we rotating logs here? This is a sensitive location with a lot going on!?
         (load-limit  (configf:lookup-number *configdat* "jobtools" "max-server-start-load" default: 3.0)))
    ;; we want the remote server to start in *toppath* so push there
    (push-directory areapath)
        (ttdat (make-tt areapath: *toppath*))
    (debug:print 0 *default-log-port* "INFO: Trying to start server (" cmdln ") ...")
    (thread-start! log-rotate)
    
     )
    ;; host.domain.tld match host?
    ;; (if (and target-host 
    ;; 	     ;; look at target host, is it host.domain.tld or ip address and does it 
    ;; 	     ;; match current ip or hostname
    ;; 	     (not (string-match (conc "("curr-host "|" curr-host"\\..*)") target-host))
    ;; 	     (not (equal? curr-ip target-host)))
    ;; 	(begin
    ;; 	  (debug:print-info 0 *default-log-port* "Starting server on " target-host ", logfile is " logfile)
    ;; 	  (setenv "TARGETHOST" target-host)))
    ;;   
    (setenv "TARGETHOST_LOGF" logfile)
    (thread-sleep! (/ (random 3000) 1000)) ;; add a random initial delay. It seems pretty common that many running tests request a server at the same time
    (debug:print 0 *default-log-port* "INFO: starting server at " (common:human-time))
    (system (conc "nbfake " cmdln))
    (unsetenv "TARGETHOST_LOGF")
    ;; (if (get-environment-variable "TARGETHOST")(unsetenv "TARGETHOST"))
    (thread-join! log-rotate)
    (pop-directory)))

     (format #t fmtstr "DB" "host:port" "PID" "age" "last mod" "state")
;; given a path to a server log return: host port startseconds server-id
;; any changes to number of elements returned by this fuction will dirctly affect server:record->url,server:record->id,server:kill,server:get-num-alive which use match let 
;; example of what it's looking for in the log file:
;;     SERVER STARTED: 10.38.175.67:50216 AT 1616502350.0 server-id: 4907e90fc55c7a09694e3f658c639cf4 

     (for-each
(define (server:logf-get-start-info logf)
  (let ((server-rx    (regexp "^SERVER STARTED: (\\S+):(\\d+) AT ([\\d\\.]+) server-id: (\\S+) pid: (\\d+)")) ;; SERVER STARTED: host:port AT timesecs server id
        (dbprep-rx    (regexp "^SERVER: dbprep"))
        (dbprep-found 0)
	(bad-dat      (list #f #f #f #f #f)))
    (handle-exceptions
     exn
     (begin
       ;; WARNING: this is potentially dangerous to blanket ignore the errors
       (if (file-exists? logf)
	   (debug:print-info 2 *default-log-port* "Unable to get server info from "logf", exn=" exn))
       bad-dat) ;; no idea what went wrong, call it a bad server
     (with-input-from-file
	 logf
       (lambda ()
        (lambda (dbfile)
	 (let loop ((inl  (read-line))
		    (lnum 0))
          (let* (
	   (if (not (eof-object? inl))
	       (let ((mlst (string-match server-rx inl))
		     (dbprep (string-match dbprep-rx inl)))
		 (if dbprep (set! dbprep-found 1))
		 (if (not mlst)
		     (if (< lnum 500) ;; give up if more than 500 lines of server log read
			 (loop (read-line)(+ lnum 1))
			 (begin 
                           (debug:print-info 0 *default-log-port* "Unable to get server info from first 500 lines of " logf )
                           bad-dat))
		     (match mlst
			    ((_ host port start server-id pid)
			     (list host
				   (string->number port)
				   (string->number start)
				   server-id
				   (string->number pid)))
			    (else
			     (debug:print 0 *current-log-port* "ERROR: did not recognise SERVER line info "mlst)
			     bad-dat))))
	       (begin 
		 (if dbprep-found
		     (begin
		       (debug:print-info 2 *default-log-port* "Server is in dbprep at " (common:human-time))
		       (thread-sleep! 0.5)) ;; was 25 sec but that blocked things from starting?
		     (debug:print-info 0 *default-log-port* "Unable to get server info from " logf " at " (seconds->time-string (current-seconds))))
		 bad-dat))))))))

            (dbfname (conc (pathname-file dbfile) ".db"))
;; ;; get a list of servers from the log files, with all relevant data
;; ;; ( mod-time host port start-time pid )
;; ;;
;; (define (server:get-list areapath #!key (limit #f))
;;   (let ((fname-rx    (regexp "^(|.*/)server-(\\d+)-(\\S+).log$"))
;; 	(day-seconds (* 24 60 60)))
;;     ;; if the directory exists continue to get the list
;;     ;; otherwise attempt to create the logs dir and then
;;     ;; continue
;;     (if (if (directory-exists? (conc areapath "/logs"))
;; 	    '()
;; 	    (if (file-write-access? areapath)
;; 		(begin
;; 		  (condition-case
;; 		   (create-directory (conc areapath "/logs") #t)
;; 		   (exn (i/o file)(debug:print 0 *default-log-port* "ERROR: Cannot create directory at " (conc areapath "/logs")))
;; 		   (exn ()(debug:print 0 *default-log-port* "ERROR: Unknown error attemtping to get server list. exn=" exn)))
;; 		  (directory-exists? (conc areapath "/logs")))
;; 		'()))
;; 
;;         ;; Get the list of server logs.
;; 	(let* (
;;                ;; For some reason, when I uncomment the below line, ext-tests sometimes starts 1000's of servers.
;;                ;; (exiting-servers (system (conc "bash -c 'rm -f `grep -il exiting " areapath "/logs/server-*-*.log 2> /dev/null`'")))
;;                (server-logs   (glob (conc areapath "/logs/server-*-*.log")))
;; 	       (num-serv-logs (length server-logs)))
;; 	  (if (or (null? server-logs) (= num-serv-logs 0))
;;               (let ()
;;                  (debug:print 2  *default-log-port* "There are no servers running at " (common:human-time))
;; 	         '()
;;               )
;; 	      (let loop ((hed  (string-chomp (car server-logs)))
;; 			 (tal  (cdr server-logs))
;; 			 (res '()))
;; 		(let* ((mod-time  (handle-exceptions
;; 				   exn
;; 				   (begin
            (sfiles   (tt:find-server *toppath* dbfname))
;; 				     (debug:print 0 *default-log-port* "server:get-list: failed to get modification time on " hed ", exn=" exn)
;; 				     (current-seconds)) ;; 0
;; 				   (file-modification-time hed))) ;; default to *very* old so log gets ignored if deleted
;; 		       (down-time (- (current-seconds) mod-time))
;; 		       (serv-dat  (if (or (< num-serv-logs 10)
;; 				  	  (< down-time 900)) ;; day-seconds))
;; 				      (server:logf-get-start-info hed)
;; 				      '())) ;; don't waste time processing server files not touched in the 15 minutes if there are more than ten servers to look at
;; 		       (serv-rec (cons mod-time serv-dat))
;; 		       (fmatch   (string-match fname-rx hed))
;; 		       (pid      (if fmatch (string->number (list-ref fmatch 2)) #f))
;; 		       (new-res  (if (null? serv-dat)
;; 				     res
;; 				     (cons (append serv-rec (list pid)) res)))) ;; any changes to number of elements in new-res will dirctly affect server:record->url,server:record->id,server:kill,server:get-num-alive which uses match let 
;; 		  (if (null? tal)
;; 		      (if (and limit
;; 			       (> (length new-res) limit))
;; 			  new-res ;; (take new-res limit)  <= need intelligent sorting before this will work
;; 			  new-res)
;; 		      (loop (string-chomp (car tal)) (cdr tal) new-res)))))))))

            )
#;(define (server:get-num-alive srvlst)
  (let ((num-alive 0))
    (for-each
     (lambda (server)
            (for-each 
              (lambda (sfile)
        (handle-exceptions
          exn
                (let (
         (begin 
          (debug:print-info 0 *default-log-port*  "Unable to get server start-time and/or mod-time from " server ", exn=" exn))
       (match-let (((mod-time host port start-time server-id pid)
		    server))
                  (sinfos (tt:get-server-info-sorted ttdat dbfname))
	 (let* ((uptime  (- (current-seconds) mod-time))
		(runtime (if start-time
			     (- mod-time start-time)
			     0)))
	   (if (< uptime 5)(set! num-alive (+ num-alive 1)))))))
     srvlst)
    num-alive))

                  )
;; ;; given a list of servers get a list of valid servers, i.e. at least
;; ;; 10 seconds old, has started and is less than 1 hour old and is
;; ;; active (i.e. mod-time < 10 seconds
;; ;;
;; ;; mod-time host port start-time pid
;; ;;
;; ;; sort by start-time descending. I.e. get the oldest first. Young servers will thus drop off
;; ;; and servers should stick around for about two hours or so.
;; ;;
;; (define (server:get-best srvlst)
;;   (let* ((nums (server:get-num-servers))
;; 	 (now  (current-seconds))
;; 	 (slst (sort
;; 		(filter (lambda (rec)
;; 			  (if (and (list? rec)
;; 				   (> (length rec) 2))
;; 			      (let ((start-time (list-ref rec 3))
;; 				    (mod-time   (list-ref rec 0)))
;; 				;; (print "start-time: " start-time " mod-time: " mod-time)
;; 				(and start-time mod-time
;; 				     (> (- now start-time) 0)    ;; been running at least 0 seconds
;; 				     (< (- now mod-time)   16)   ;; still alive - file touched in last 16 seconds
;; 				     (or (not (configf:lookup *configdat* "server" "runtime")) ;; skip if not set
                  (for-each 
;; 					 (< (- now start-time)       
;; 					    (+ (- (string->number (configf:lookup *configdat* "server" "runtime"))
;; 					       180)
;; 					    (random 360)))) ;; under one hour running time +/- 180
;; 				     ))
;; 			      #f))
;; 			srvlst)
;; 		(lambda (a b)
                     (lambda (sinfo)
;; 		  (< (list-ref a 3)
;; 		     (list-ref b 3))))))
;;     (if (> (length slst) nums)
;; 	(take slst nums)
;; 	slst)))

;; ;; switch from server:get-list to server:get-servers-info
;; ;;
;; (define (server:get-first-best areapath)
;;   (let ((srvrs (server:get-best (server:get-list areapath))))
;;     (if (and srvrs
;; 	     (not (null? srvrs)))
;; 	(car srvrs)
;; 	#f)))
;; 
;; (define (server:get-rand-best areapath)
;;   (let ((srvrs (server:get-best (server:get-list areapath))))
;;     (if (and (list? srvrs)
;; 	     (not (null? srvrs)))
;; 	(let* ((len (length srvrs))
                       (let* (
;; 	       (idx (random len)))
;; 	  (list-ref srvrs idx))
                         (db (list-ref sinfo 5))
;; 	#f)))

                         (pid (list-ref sinfo 4))
(define (server:record->id servr)
  (handle-exceptions
   exn
   (begin 
     (debug:print-info 0 *default-log-port*  "Unable to get server id from " servr ", exn=" exn)     
   #f)
  (match-let (((host port start-time server-id pid)
	       servr))
    (if server-id
	server-id
	#f))))

                         (host (list-ref sinfo 0))
(define (server:record->url servr)
  (handle-exceptions
   exn
   (begin 
     (debug:print-info 0 *default-log-port*  "Unable to get server url from " servr ", exn=" exn)     
   #f)
  (match-let (((host port start-time server-id pid)
	       servr))
    (if (and host port)
	(conc host ":" port)
	#f))))

                         (port (list-ref sinfo 1))

;; if server-start-last exists, and wasn't old enough, wait <idle time> + 1, then call this function recursively until it is old enough.
;; if it is old enough, overwrite it and wait 0.25 seconds.
;; if it then has the wrong server key, wait <idle time> + 1 and call this function recursively.
;;
#;(define (server:wait-for-server-start-last-flag areapath)
  (let* ((start-flag (conc areapath "/logs/server-start-last"))
	 ;;; THIS INTERACTS WITH [server] timeout. Suggest using 0.1 or above for timeout (6 seconds)
	 (idletime    (configf:lookup-number *configdat* "server" "idletime" default: 4))
	 (server-key (conc (get-host-name) "-" (current-process-id))))
    (if (file-exists? start-flag)
	(let* ((fmodtime (file-modification-time start-flag))
	       (delta    (- (current-seconds) fmodtime))
	       (old-enough   (> delta idletime))
               (new-server-key ""))
          ;; write start-flag file, wait 0.25s, then if previously the start-flag file was older than <idletime> seconds, and the new file still has the same server key as you just wrote, return #t.
	  ;; the intention is to make sure nfs can read the file we just wrote, and make sure it was written by us, and not another process.
           (if (and old-enough
		    (begin
                      (debug:print-info 2 *default-log-port* "Writing " start-flag)
		      (with-output-to-file start-flag (lambda () (print server-key)))
		      (thread-sleep! 0.25)
		      (set! new-server-key (with-input-from-file start-flag (lambda () (read-line))))
		      (equal? server-key new-server-key)))
	       #t
               ;; If either of the above conditions is not true, print a "Gating server start" message, wait <idle-time> + 1, then call this function recursively. 
	       (begin
		 (debug:print-info 0 *default-log-port* "Gating server start, last start: "
				   (seconds->time-string fmodtime) ", time since last start: " delta ", required idletime: " idletime ", gating reason:" (if old-enough "another job started a server" "too soon to start another server"))
		 
		 (thread-sleep! ( + 1 idletime))
		 (server:wait-for-server-start-last-flag areapath)))))))

;; oldest server alive determines host then choose random of youngest
;; five servers on that host
;;
(define (server:get-servers-info areapath)
  ;; (assert *toppath* "FATAL: server:get-servers-info called before *toppath* has been set.")
  (let* ((servinfodir (server:get-servinfo-dir areapath))) ;; (conc *toppath*"/.servinfo")))
    (if (not (file-exists? servinfodir))
	(create-directory servinfodir))
    (let* ((allfiles    (glob (conc servinfodir"/*")))
	   (res         (make-hash-table)))
      (for-each
       (lambda (f)
	 (let* ((hostport  (pathname-strip-directory f))
		(serverdat (server:logf-get-start-info f)))
	   (match serverdat
	     ((host port start server-id pid)
                         (server-id (list-ref sinfo 3))
	      (if (and host port start server-id pid)
		  (hash-table-set! res hostport serverdat)
		  (debug:print-info 2 *default-log-port* "bad server info for "f": "serverdat)))
	     (else
	      (debug:print-info 2 *default-log-port* "bad server info for "f": "serverdat)))))
       allfiles)
      res)))

                         (age (seconds->hr-min-sec (- (current-seconds) (list-ref sinfo 2))))
;; check the .servinfo directory, are there other servers running on this
;; or another host?
;;
;; returns #t => ok to start another server
;;         #f => not ok to start another server
;;
(define (server:minimal-check areapath)
  (server:clean-up-old areapath)
  (let* ((srvdir      (server:get-servinfo-dir areapath)) ;; (conc areapath"/.servinfo"))
	 (servrs      (glob (conc srvdir"/*")))
	 (thishostip  (server:get-best-guess-address (get-host-name)))
	 (thisservrs  (glob (conc srvdir"/"thishostip":*")))
	 (homehostinf (server:choose-server areapath 'homehost))
	 (havehome    (car homehostinf))
	 (wearehome   (cdr homehostinf)))
    (debug:print-info 0 *default-log-port* thishostip", have homehost: "havehome", we are homehost: "wearehome
		      ", numservers: "(length thisservrs))
    (cond
     ((not havehome) #t) ;; no homehost yet, go for it
     ((and havehome wearehome (< (length thisservrs) 20)) #t) ;; we are home and less than 20 servers, ok to start another
     ((and havehome (not wearehome)) #f)     ;; we are not the home host
     ((and havehome wearehome (>= (length thisservrs) 20)) #f) ;; have enough running
     (else
      (debug:print 0 *default-log-port* "WARNING: Unrecognised scenario, servrs="servrs", thishostip="thishostip", thisservrs="thisservrs)
      #t))))
	 

                         (last-mod (seconds->string (list-ref sinfo 2)))
                         (killed (system (conc "ssh " host " kill " pid " > /dev/null")))
(define server-last-start 0)


                         (dummy2 (sleep 1))
                         (state (if (> (system (conc "ssh " host " ps " pid " > /dev/null")) 0) "dead" "alive"))
;; oldest server alive determines host then choose random of youngest
;; five servers on that host
;;
;; mode:
;;   best - get best server (random of newest five)
;;   home - get home host based on oldest server
;;   info - print info
(define (server:choose-server areapath #!optional (mode 'best))
  ;; age is current-starttime
  ;; find oldest alive
  ;;   1. sort by age ascending and ping until good
  ;; find alive rand from youngest
  ;;   1. sort by age descending
  ;;   2. take five
  ;;   3. check alive, discard if not and repeat
  ;; first we clean up old server files
  (assert (eq? (rmt:transport-mode) 'http) "FATAL: server:run called with rmt:transport-mode="(rmt:transport-mode))
  (server:clean-up-old areapath)
  (let* ((since-last (- (current-seconds) server-last-start))
        (server-start-delay 10))     
    (if ( < (- (current-seconds) server-last-start) 10 )
      (begin
        (debug:print 2 *default-log-port* "server:choose-server: seconds since last server start: " (- (current-seconds) server-last-start))
        (debug:print 2 *default-log-port* "server:choose-server: last server start less than " server-start-delay " seconds ago. Sleeping " server-start-delay " seconds")
        (thread-sleep! server-start-delay)
      )
                            )
      (debug:print 2 *default-log-port* "server:choose-server: seconds since last server start: " (- (current-seconds) server-last-start))
    )
  )
  (let* ((serversdat  (server:get-servers-info areapath))
	 (servkeys    (hash-table-keys serversdat))
	 (by-time-asc (if (not (null? servkeys)) ;; NOTE: Oldest is last
			  (sort servkeys ;; list of "host:port"
				(lambda (a b)
				  (>= (list-ref (hash-table-ref serversdat a) 2)
				      (list-ref (hash-table-ref serversdat b) 2))))
			  '())))
    (debug:print 2 *default-log-port* "server:choose-server: serversdat: " serversdat)
    (debug:print 2 *default-log-port* "server:choose-server: servkeys: " servkeys)
    (if (not (null? by-time-asc))
	(let* ((oldest     (last by-time-asc))
	       (oldest-dat (hash-table-ref serversdat oldest))
	       (host       (list-ref oldest-dat 0))
	       (all-valid  (filter (lambda (x)
				     (equal? host (list-ref (hash-table-ref serversdat x) 0)))
				   by-time-asc))
	       (best-ten  (lambda ()
			     (if (> (length all-valid) 11)
				 (take (drop-right all-valid 1) 10) ;; remove the oldest from consideration so it can age out
				 (if (> (length all-valid) 8)
				     (drop-right all-valid 1)
				     all-valid))))
	       (names->dats (lambda (names)
			      (map (lambda (x)
				     (hash-table-ref serversdat x))
				   names)))
	       (am-home?    (lambda ()
			      (let* ((currhost (get-host-name))
				     (bestadrs (server:get-best-guess-address currhost)))
				(or (equal? host currhost)
				    (equal? host bestadrs))))))
                         (format #t fmtstr db (conc host ":" port) pid age last-mod state)
	  (case mode
	    ((info)
	     (debug:print 0 *default-log-port* "oldest: "oldest-dat", selected host: "host", all-valid: "all-valid)
	     (debug:print 0 *default-log-port* "youngest: "(hash-table-ref serversdat (car all-valid))))
	    ((home)     host)
	    ((homehost) (cons host (am-home?))) ;; shut up old code
	    ((home?)    (am-home?))
	    ((best-ten)(names->dats (best-ten)))
	    ((all-valid)(names->dats all-valid))
	    ((best)     (let* ((best-ten (best-ten))
			       (len       (length best-ten)))
			  (hash-table-ref serversdat (list-ref best-ten (random len)))))
	    ((count)(length all-valid))
	    (else
	     (debug:print 0 *default-log-port* "ERROR: invalid command "mode)
	     #f)))
	(begin
	  (server:run areapath)
          (set! server-last-start (current-seconds))
	  ;; (thread-sleep! 3)
	  (case mode
	    ((homehost) (cons #f #f))
                         (system (conc "rm " sfile))
	    (else	#f))))))

                       )
(define (server:get-servinfo-dir areapath)
  (let* ((spath (conc areapath"/.servinfo")))
    (if (not (file-exists? spath))
	(create-directory spath #t))
    spath))

                     )
(define (server:clean-up-old areapath)
  ;; any server file that has not been touched in ten minutes is effectively dead
  (let* ((sfiles (glob (conc (server:get-servinfo-dir areapath)"/*"))))
    (for-each
     (lambda (sfile)
       (let* ((modtime (handle-exceptions
			   exn
			 (begin
                     sinfos
			   (debug:print 0 *default-log-port* "WARNING: failed to get modification file for "sfile)
			   (current-seconds))
			 (file-modification-time sfile))))
	 (if (and (number? modtime)
		  (> (- (current-seconds) modtime)
		     600))
	     (begin
	       (debug:print 0 *default-log-port* "WARNING: found old server info file "sfile", removing it.")
	       (handle-exceptions
		   exn
		 (debug:print 0 *default-log-port* "WARNING: failed to delete old server info file "sfile)
		 (delete-file sfile))))))
     sfiles)))

                  )
;; would like to eventually get rid of this
;;
(define (common:on-homehost?)
  (if (eq? (rmt:transport-mode) 'http)
      (server:choose-server *toppath* 'home?)
      #t)) ;; there is no homehost for tcp and nfs is always on home so #t should work

                ) 
;; kind start up of server, wait before allowing another server for a given
;; area to be launched
;;
(define (server:kind-run areapath)
  ;; look for $MT_RUN_AREA_HOME/logs/server-start-last
  ;; and wait for it to be at least <server idletime> seconds old
  ;; (server:wait-for-server-start-last-flag areapath)
              )
  (let loop ()
    (if (> (alist-ref 'adj-proc-load (common:get-normalized-cpu-load #f)) 2)
	(begin
	  (if (common:low-noise-print 30 "our-host-load")
	      (debug:print 0 *default-log-port* "WARNING: system load is high, waiting to start server."))
	  (loop))))
  (if (< (server:choose-server areapath 'count) 20)
      (server:run areapath))
  #;(if (not (server:check-if-running areapath)) ;; why try if there is already a server running?
      (let* ((lock-file    (conc areapath "/logs/server-start.lock")))
	(let* ((start-flag (conc areapath "/logs/server-start-last")))
	  (common:simple-file-lock-and-wait lock-file expire-time: 25)
	  (debug:print-info  2 *default-log-port* "server:kind-run: touching " start-flag)
	  (system (conc "touch " start-flag)) ;; lazy but safe
	  (server:run areapath)
	  (thread-sleep! 20) ;; don't release the lock for at least a few seconds. And allow time for the server startup to get to "SERVER STARTED".
	  (common:simple-file-release-lock lock-file)))
      (debug:print-info 0 *default-log-port* "Found server already running. NOT trying to start another.")))

              sfiles
;; this one seems to be the general entry point
;;
(define (server:start-and-wait areapath #!key (timeout 60))
  (let ((give-up-time (+ (current-seconds) timeout)))
    (let loop ((server-info (server:check-if-running areapath))
	       (try-num    0))
      (if (or server-info
	      (> (current-seconds) give-up-time)) ;; server-url will be #f if no server available.
	  (server:record->url server-info)
	  (let* ( (servers (server:choose-server areapath 'all-valid))
                (num-ok (if servers (length (server:choose-server areapath 'all-valid)) 0)))
	    (if (and (> try-num 0)  ;; first time through simply wait a little while then try again
		     (< num-ok 1))  ;; if there are no decent candidates for servers then try starting a new one
		(server:run areapath))
	    (thread-sleep! 5)
	    (loop (server:check-if-running areapath)
		  (+ try-num 1)))))))

            )
(define (server:get-num-servers #!key (numservers 2))
  (let ((ns (string->number
	     (or (configf:lookup *configdat* "server" "numservers") "notanumber"))))
    (or ns numservers)))

          )
;; no longer care if multiple servers are started by accident. older servers will drop off in time.
;;
(define (server:check-if-running areapath) ;;  #!key (numservers "2"))
  (let* ((ns            (server:get-num-servers)) ;; get the setting the for maximum number of servers allowed
	 (servers       (server:choose-server areapath 'best-ten))) ;; (server:get-best (server:get-list areapath))))
    (if (or (and servers
		 (null? servers))
	    (not servers))
	    ;; (and (list? servers)
	    ;;	 (< (length servers) (+ 1 (random ns))))) ;; somewhere between 1 and numservers
        #f
        (let loop ((hed (car servers))
                   (tal (cdr servers)))
          (let ((res (server:check-server hed)))
            (if res
                hed
                (if (null? tal)
                    #f
                    (loop (car tal)(cdr tal)))))))))

       )
;; ping the given server
;;
(define (server:check-server server-record)
  (let* ((server-url (server:record->url server-record))
         (server-id  (server:record->id server-record)) 
         (res        (server:ping server-url server-id)))
    (if res
        server-url
	#f)))

(define (server:kill servr)
  (handle-exceptions
    exn
    (begin 
      (debug:print-info 0 *default-log-port*  "Unable to get host and/or port from " servr ", exn=" exn)     
    #f)
  (match-let (((hostname port start-time server-id pid)
	       servr))
    (tasks:kill-server hostname pid))))

;; ;; called in megatest.scm, host-port is string hostname:port
;; ;;
;; ;; NOTE: This is NOT called directly from clients as not all transports support a client running
;; ;;       in the same process as the server.
;; ;;
;; (define (server:ping host:port server-id #!key (do-exit #f))
;;   (let* ((host-port (cond
;; 		     ((string? host:port)
;; 		      (let ((slst (string-split   host:port ":")))
;; 			(if (eq? (length slst) 2)
;; 			    (list (car slst)(string->number (cadr slst)))
;; 			    #f)))
;; 		     (else
;; 		      #f))))
;;     (cond
;;      ((and (list? host-port)
;; 	   (eq? (length host-port) 2))
;;       (let* ((myrunremote (make-and-init-remote *toppath*))
;; 	     (iface       (car host-port))
;; 	     (port        (cadr host-port))
;; 	     (server-dat  (client:connect iface port server-id myrunremote))
;; 	     (login-res   (rmt:login-no-auto-client-setup myrunremote)))
;; 	(http-transport:close-connections myrunremote)
;; 	(if (and (list? login-res)
;; 		 (car login-res))
;; 	    (begin
;; 	      ;; (print "LOGIN_OK")
;; 	      (if do-exit (exit 0))
;; 	      #t)
;; 	    (begin
;; 	      ;; (print "LOGIN_FAILED")
;; 	      (if do-exit (exit 1))
;; 	      #f))))
;;      (else 
;;       (if host:port
;; 	  (debug:print 0 *default-log-port*  "ERROR: bad host:port "host:port))
;;       (if do-exit
;; 	  (exit 1)
;; 	  #f)))))
;; 
;; ;; run ping in separate process, safest way in some cases
;; ;;
;; (define (server:ping-server ifaceport)
;;   (with-input-from-pipe 
;;    (conc (common:get-megatest-exe) " -ping " ifaceport)
;;    (lambda ()
;;      (let loop ((inl (read-line))
;; 		(res "NOREPLY"))
       dbfiles
;;        (if (eof-object? inl)
;; 	   (case (string->symbol res)
;; 	     ((NOREPLY)  #f)
;; 	     ((LOGIN_OK) #t)
;; 	     (else       #f))
;; 	   (loop (read-line) inl))))))
;; 
;; ;; NOT USED (well, ok, reference in rpc-transport but otherwise not used).
;; ;;
;; (define (server:login toppath)
;;   (lambda (toppath)
;;     (set! *db-last-access* (current-seconds)) ;; might not be needed.
;;     (if (equal? *toppath* toppath)
;; 	#t
;; 	#f)))

     )
;; timeout is hms string: 1h 5m 3s, default is 1 minute
;; This is currently broken. Just use the number of hours with no unit.
;; Default is 600 seconds.
;;
(define (server:expiration-timeout)
  (let* ((tmo (configf:lookup *configdat* "server" "timeout")))
    (if (string? tmo)
     ;; remove this db, because otherwise metadata contains records for old servers, and this causes a problem with db:no-sync-get-lock-with-id.
     (if (file-exists? (conc *toppath* "/.mtdb/no-sync.db"))
	(let* ((num (string->number tmo)))
	  (if num
	      (* 3600 num)
	      (common:hms-string->seconds tmo)))
	600 ;; this is the default
	)))

       (delete-file (conc *toppath* "/.mtdb/no-sync.db"))
(define (server:get-best-guess-address hostname)
  (let ((res #f))
    (for-each 
     (lambda (adr)
       (if (not (eq? (u8vector-ref adr 0) 127))
	   (set! res adr)))
     ;; NOTE: This can fail when there is no mention of the host in /etc/hosts. FIXME
     (vector->list (hostinfo-addresses (hostname->hostinfo hostname))))
    (string-intersperse 
     (map number->string
	  (u8vector->list
	   (if res res (hostname->ip hostname)))) ".")))

     )
;; moving this here as it needs access to db and cannot be in common.
;;

  )
(define (server:get-bruteforce-syncer dbstruct #!key (fork-to-background #f) (persist-until-sync #f))
  (debug:print "WARNING: bruteforce-syncer is called but has been disabled!")
  (lambda ()
    (debug:print "WARNING: bruteforce-syncer is called but has been disabled!")))

)