;;======================================================================
;; Copyright 2017, Matthew Welland.
;;
;; This file is part of Megatest.
;;
;; Megatest is free software: you can redistribute it and/or modify
;; it under the terms of the GNU General Public License as published by
;; the Free Software Foundation, either version 3 of the License, or
;; (at your option) any later version.
;;
;; Megatest is distributed in the hope that it will be useful,
;; but WITHOUT ANY WARRANTY; without even the implied warranty of
;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
;; GNU General Public License for more details.
;;
;; 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 servermod))
(declare (uses commonmod))
(declare (uses configfmod))
(declare (uses dbmod))
(module servermod
*
(import scheme chicken data-structures extras ports files)
(import (prefix sqlite3 sqlite3:) posix
typed-records srfi-18 srfi-1 srfi-69 srfi-4
message-digest hostinfo
regex matchable
md5)
(import commonmod)
(import configfmod)
(import dbmod)
(define (server:make-server-url hostport)
(if (not hostport)
#f
(conc "http://" (car hostport) ":" (cadr hostport))))
;;======================================================================
;; 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)))))))
;; 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
(db:obj->string (vector success/fail query-sig result)))
;; (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 a path to a server log return: host port startseconds
;; 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 uses match let
;;
(define (server:logf-get-start-info logf)
(let ((rx (regexp "^SERVER STARTED: (\\S+):(\\d+) AT ([\\d\\.]+) server-id: (\\S+)"))) ;; SERVER STARTED: host:port AT timesecs server id
(handle-exceptions
exn
(begin
(debug:print-info 0 *default-log-port* "Unable to get server info from " logf ", exn=" exn)
(list #f #f #f #f)) ;; no idea what went wrong, call it a bad server
(with-input-from-file
logf
(lambda ()
(let loop ((inl (read-line))
(lnum 0))
(if (not (eof-object? inl))
(let ((mlst (string-match rx inl)))
(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 )
(list #f #f #f #f)))
(let ((dat (cdr mlst)))
(list (car dat) ;; host
(string->number (cadr dat)) ;; port
(string->number (caddr dat))
(cadr (cddr dat))))))
(begin
(debug:print-info 0 *default-log-port* "Unable to get server info from " logf " at " (current-seconds))
(list #f #f #f #f)))))))))
;; get a list of servers 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")))
'()))
(let* ((server-logs (glob (conc areapath "/logs/server-*.log")))
(num-serv-logs (length server-logs)))
(if (null? server-logs)
'()
(let loop ((hed (car server-logs))
(tal (cdr server-logs))
(res '()))
(let* ((mod-time (handle-exceptions
exn
(begin
(debug:print 0 *default-log-port* "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 (car tal)(cdr tal) new-res)))))))))
(define (server:get-num-alive srvlst)
(let ((num-alive 0))
(for-each
(lambda (server)
(handle-exceptions
exn
(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))
(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
(< (- now start-time)
(+ (- (string->number (configf:lookup *configdat* "server" "runtime"))
180)
(random 360)))) ;; under one hour running time +/- 180
))
#f))
srvlst)
(lambda (a b)
(< (list-ref a 3)
(list-ref b 3))))))
(if (> (length slst) nums)
(take slst nums)
slst)))
(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))
(idx (random len)))
(list-ref srvrs idx))
#f)))
(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 (((mod-time host port start-time server-id pid)
servr))
(if server-id
server-id
#f))))
(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 (((mod-time host port start-time server-id pid)
servr))
(if (and host port)
(conc host ":" port)
#f))))
(define (server:get-client-signature) ;; BB> why is this proc named "get-"? it returns nothing -- set! has not return value.
(if *my-client-signature* *my-client-signature*
(let ((sig (server:mk-signature)))
(set! *my-client-signature* sig)
*my-client-signature*)))
;; wait for server=start-last to be three seconds old
;;
(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)
(reftime (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))
(all-go (> delta reftime)))
(if (and all-go
(begin
(with-output-to-file start-flag
(lambda ()
(print server-key)))
(thread-sleep! 0.25)
(let ((res (with-input-from-file start-flag
(lambda ()
(read-line)))))
(equal? server-key res))))
#t ;; (system (conc "touch " start-flag)) ;; lazy but safe
(begin
(debug:print-info 0 *default-log-port* "Gating server start, last start: "
fmodtime ", delta: " delta ", reftime: " reftime ", all-go=" all-go)
(thread-sleep! reftime)
(server:wait-for-server-start-last-flag areapath)))))))
(define (server:get-num-servers #!key (numservers 2))
(let ((ns (string->number
(or (configf:lookup *configdat* "server" "numservers") "notanumber"))))
(or ns numservers)))
(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 (((mod-time 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.
;;
;; 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"))
(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
;;
(define (server:expiration-timeout)
(let ((tmo (configf:lookup *configdat* "server" "timeout")))
(if (and (string? tmo)
(common:hms-string->seconds tmo)) ;; BUG: hms-string->seconds is broken, if given "10" returns 0. Also, it doesn't belong in this logic unless the string->number is changed below
(* 3600 (string->number tmo))
60)))
(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)))) ".")))
;; (define server:sync-lock-token "SERVER_SYNC_LOCK")
;; (define (server:release-sync-lock)
;; (db:no-sync-del! *no-sync-db* server:sync-lock-token))
;; (define (server:have-sync-lock?)
;; (let* ((have-lock-pair (db:no-sync-get-lock *no-sync-db* server:sync-lock-token))
;; (have-lock? (car have-lock-pair))
;; (lock-time (cdr have-lock-pair))
;; (lock-age (- (current-seconds) lock-time)))
;; (cond
;; (have-lock? #t)
;; ((>lock-age
;; (* 3 (configf:lookup-number *configdat* "server" "minimum-intersync-delay" default: 180)))
;; (server:release-sync-lock)
;; (server:have-sync-lock?))
;; (else #f))))
;; 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))
(let* ((sqlite-exe (or (get-environment-variable "MT_SQLITE3_EXE"))) ;; defined in cfg.sh
(sync-log (or ;; (args:get-arg "-sync-log")
(conc *toppath* "/logs/sync-" (current-process-id) "-" (get-host-name) ".log")))
(tmp-area (common:get-db-tmp-area))
(tmp-db (conc tmp-area "/megatest.db"))
(staging-file (conc *toppath* "/.megatest.db"))
(mtdbfile (conc *toppath* "/megatest.db"))
(lockfile (common:get-sync-lock-filepath))
(sync-cmd-core (conc sqlite-exe" " tmp-db " .dump | "sqlite-exe" " staging-file "&>"sync-log))
(sync-cmd (if fork-to-background
(conc "/usr/bin/env NBFAKE_LOG="*toppath*"/logs/last-server-sync-"(current-process-id)".log nbfake \""sync-cmd-core" && /bin/mv -f " staging-file " " mtdbfile" \"")
sync-cmd-core))
(default-min-intersync-delay 2)
(min-intersync-delay (configf:lookup-number *configdat* "server" "minimum-intersync-delay" default: default-min-intersync-delay))
(default-duty-cycle 0.1)
(duty-cycle (configf:lookup-number *configdat* "server" "sync-duty-cycle" default: default-duty-cycle))
(last-sync-seconds 10) ;; we will adjust this to a measurement and delay last-sync-seconds * (1 - duty-cycle)
(calculate-off-time (lambda (work-duration duty-cycle)
(* (/ (- 1 duty-cycle) duty-cycle) last-sync-seconds)))
(off-time min-intersync-delay) ;; adjusted in closure below.
(do-a-sync
(lambda ()
;; (BB> "Start do-a-sync with fork-to-background="fork-to-background" persist-until-sync="persist-until-sync)
(let* ((finalres
(let retry-loop ((num-tries 0))
(if (common:simple-file-lock lockfile)
(begin
(cond
((not (or fork-to-background persist-until-sync))
(debug:print 0 *default-log-port* "INFO: syncer thread sleeping for max of (server.minimum-intersync-delay="min-intersync-delay
" , off-time="off-time" seconds ]")
(thread-sleep! (max off-time min-intersync-delay)))
(else
(debug:print 0 *default-log-port* "INFO: syncer thread NOT sleeping ; maybe time-to-exit...")))
(if (not (configf:lookup *configdat* "server" "disable-db-snapshot"))
(common:snapshot-file mtdbfile subdir: ".db-snapshot"))
(delete-file* staging-file)
(let* ((start-time (current-milliseconds))
(res (system sync-cmd))
(dbbackupfile (conc mtdbfile ".backup"))
(res2
(cond
((eq? 0 res )
(handle-exceptions
exn
#f
(if (file-exists? dbbackupfile)
(delete-file* dbbackupfile)
)
(if (eq? 0 (file-size sync-log))
(delete-file* sync-log))
(system (conc "/bin/mv " staging-file " " mtdbfile))
(set! last-sync-seconds (/ (- (current-milliseconds) start-time) 1000))
(set! off-time (calculate-off-time
last-sync-seconds
(cond
((and (number? duty-cycle) (> duty-cycle 0) (< duty-cycle 1))
duty-cycle)
(else
(debug:print 0 *default-log-port* "WARNING: ["(common:human-time)"] server.sync-duty-cycle is invalid. Should be a number between 0 and 1, but "duty-cycle" was specified. Using default value: "default-duty-cycle)
default-duty-cycle))))
(debug:print 1 *default-log-port* "INFO: ["(common:human-time)"] pid="(current-process-id)" SYNC took "last-sync-seconds" sec")
(debug:print 1 *default-log-port* "INFO: ["(common:human-time)"] pid="(current-process-id)" SYNC took "last-sync-seconds" sec ; with duty-cycle of "duty-cycle" off time is now "off-time)
'sync-completed))
(else
(system (conc "/bin/cp "sync-log" "sync-log".fail"))
(debug:print 0 *default-log-port* "ERROR: ["(common:human-time)"] Sync failed. See log at "sync-log".fail")
(if (file-exists? (conc mtdbfile ".backup"))
(system (conc "/bin/cp "mtdbfile ".backup " mtdbfile)))
#f))))
(common:simple-file-release-lock lockfile)
;; (BB> "released lockfile: " lockfile)
#;(when (common:file-exists? lockfile)
(BB> "DID NOT ACTUALLY RELEASE LOCKFILE"))
res2) ;; end let
);; end begin
;; else
(cond
(persist-until-sync
(thread-sleep! 1)
(debug:print 1 *default-log-port* "INFO: ["(common:human-time)"] pid="(current-process-id)" other SYNC in progress; we're in a fork-to-background so we need to succeed. Let's wait a jiffy and and try again. num-tries="num-tries" (waiting for lockfile="lockfile" to disappear)")
(retry-loop (add1 num-tries)))
(else
(thread-sleep! (max off-time (+ last-sync-seconds min-intersync-delay)))
(debug:print 1 *default-log-port* "INFO: ["(common:human-time)"] pid="(current-process-id)" other SYNC in progress; not syncing.")
'parallel-sync-in-progress))
) ;; end if got lockfile
)
))
;; (BB> "End do-a-sync with fork-to-background="fork-to-background" persist-until-sync="persist-until-sync" and result="finalres)
finalres)
) ;; end lambda
))
do-a-sync))
;; (define (debug:print . params) #f)
;; (define (debug:print-info . params) #f)
;;
;; (define (set-functions dbgp dbgpinfo)
;; (set! debug:print dbgp)
;; (set! debug:print-info dbgpinfo))
)