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dbmgr.scm at [6c303b59b4]
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File ulex-none/dbmgr.scm artifact 66aa956084 part of check-in 6c303b59b4


;;======================================================================
;; Copyright 2022, 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 dbmgrmod))

(declare (uses ulex))
(declare (uses apimod))
(declare (uses pkts))
(declare (uses commonmod))
(declare (uses dbmod))
(declare (uses mtargs))
(declare (uses portloggermod))
(declare (uses debugprint))

(module dbmgrmod
    *

(import scheme
	chicken.base
	chicken.condition
	chicken.file
	chicken.format
	chicken.port
	chicken.process
	chicken.process-context
	chicken.process-context.posix
	chicken.sort
	chicken.string
	chicken.time
	
	(prefix sqlite3 sqlite3:)
	matchable
	md5
	message-digest
	regex
	s11n
	srfi-1
	srfi-18
	srfi-69
	system-information
	typed-records
	
	pkts
	ulex

	commonmod
	apimod
	dbmod
	debugprint
	(prefix mtargs args:)
	portloggermod
	)

;; ;; Configurations for server
;; ;; (tcp-buffer-size 2048)
;; ;; (max-connections 2048) 
;; 
;; ;; info about me as a listener and my connections to db servers
;; ;; stored (for now) in *db-serv-info*
;; ;;
;; (defstruct servdat
;;   (host #f)
;;   (port #f)
;;   (uuid #f)
;;   (dbfile #f)
;;   (uconn   #f) ;; this is the listener *FOR THIS PROCESS*
;;   (mode    #f)
;;   (status 'starting)
;;   (trynum 0) ;; count the number of ports we've tried
;;   (conns  (make-hash-table)) ;; apath/dbname => conndat
;;   ) 
;; 
;; (define *db-serv-info* (make-servdat))
;; 
;; (define (servdat->url sdat)
;;   (conc (servdat-host sdat)":"(servdat-port sdat)))
;; 
;; ;; db servers contact info
;; ;;
;; (defstruct conndat
;;   (apath    #f)
;;   (dbname   #f)
;;   (fullname #f)
;;   (hostport #f)
;;   (ipaddr   #f)
;;   (port     #f)
;;   (srvpkt   #f)
;;   (srvkey   #f)
;;   (lastmsg  0)
;;   (expires  0))
;; 
;; (define *srvpktspec*
;;   `((server (host    . h)
;; 	    (port    . p)
;; 	    (servkey . k)
;; 	    (pid     . i)
;; 	    (ipaddr  . a)
;; 	    (dbpath  . d))))
;; 
;; ;;======================================================================
;; ;;  S U P P O R T   F U N C T I O N S
;; ;;======================================================================
;; 
;; ;; set up the api proc, seems like there should be a better place for this?
;; ;;
;; ;; IS THIS NEEDED ANYMORE? TODO - REMOVE IF POSSIBLE
;; ;;
;; ;; (define api-proc (make-parameter conc))
;; ;; (api-proc api:execute-requests)
;; 
;; ;; do we have a connection to apath dbname and
;; ;; is it not expired? then return it
;; ;;
;; ;; else setup a connection
;; ;;
;; ;; if that fails, return '(#f "some reason") ;; NB// convert to raising an exception
;; ;;
;; (define (rmt:get-conn remdat apath dbname)
;;   (let* ((fullname (db:dbname->path apath dbname)))
;;     (hash-table-ref/default (servdat-conns remdat) fullname #f)))
;; 
;; (define (rmt:drop-conn remdat apath dbname)
;;   (let* ((fullname (db:dbname->path apath dbname)))
;;     (hash-table-delete! (servdat-conns remdat) fullname)))
;;   
;; (define (rmt:find-main-server uconn apath dbname)
;;   (let* ((pktsdir     (get-pkts-dir apath))
;; 	 (all-srvpkts (get-all-server-pkts pktsdir *srvpktspec*))
;; 	 (viable-srvs (get-viable-servers all-srvpkts dbname)))
;;     (get-the-server uconn apath viable-srvs)))
;; 
;; 
;; (define *connstart-mutex* (make-mutex))
;; (define *last-main-start* 0)
;; 
;; ;; looks for a connection to main, returns if have and not exired
;; ;; creates new otherwise
;; ;; 
;; ;; connections for other servers happens by requesting from main
;; ;;
;; ;; TODO: This is unnecessarily re-creating the record in the hash table
;; ;;
;; (define (rmt:open-main-connection remdat apath)
;;   (let* ((fullpath (db:dbname->path apath ".db/main.db"))
;; 	 (conns    (servdat-conns remdat))
;; 	 (conn     (rmt:get-conn remdat apath ".db/main.db")) ;; (hash-table-ref/default conns fullpath #f)) ;; TODO - create call for this
;; 	 (start-rmt:run (lambda ()
;; 			  (let* ((th1 (make-thread (lambda ()(rmt:run (get-host-name))) "non-db mode server")))
;; 			    (thread-start! th1)
;; 			    (thread-sleep! 1)
;; 			    (let loop ((count 0))
;; 			      (assert (< count 30) "FATAL: responder failed to initialize in rmt:open-main-connection")
;; 			      (if (or (not *db-serv-info*)
;; 				      (not (servdat-uconn *db-serv-info*)))
;; 				  (begin
;; 				    (thread-sleep! 1)
;; 				    (loop (+ count 1)))
;; 				  (begin
;; 				    (servdat-mode-set! *db-serv-info* 'non-db)
;; 				    (servdat-uconn *db-serv-info*)))))))
;; 	 (myconn    (servdat-uconn *db-serv-info*)))
;;     (cond
;;      ((not myconn)
;;       (start-rmt:run)
;;       (rmt:open-main-connection remdat apath))
;;      ((and conn                                             ;; conn is NOT a socket, just saying ...
;; 	   (< (current-seconds) (conndat-expires conn)))
;;       #t) ;; we are current and good to go - we'll deal elsewhere with a server that was killed or died 
;;      ((and conn
;; 	   (>= (current-seconds)(conndat-expires conn)))
;;       (debug:print-info 0 *default-log-port* "connection to "fullpath" server expired. Reconnecting.")
;;       (rmt:drop-conn remdat apath ".db/main.db") ;;
;;       (rmt:open-main-connection remdat apath))
;;      (else
;;       ;; Below we will find or create and connect to main
;;       (debug:print-info 0 *default-log-port* "rmt:open-main-connection - starting from scratch")
;;       (let* ((dbname         (db:run-id->dbname #f))
;; 	     (the-srv        (rmt:find-main-server myconn apath dbname))
;; 	     (start-main-srv (lambda () ;; call IF there is no the-srv found
;; 			       (mutex-lock! *connstart-mutex*)
;; 			       (if (> (- (current-seconds) *last-main-start*) 5) ;; at least four seconds since last attempt to start main server
;; 				   (begin
;; 				     (api:run-server-process apath dbname)
;; 				     (set! *last-main-start* (current-seconds))
;; 				     (thread-sleep! 1))
;; 				   (thread-sleep! 0.25))
;; 			       (mutex-unlock! *connstart-mutex*)
;; 			       (rmt:open-main-connection remdat apath) ;; TODO: Add limit to number of tries
;; 			       )))
;; 	(if (not the-srv) ;; have server, try connecting to it
;; 	    (start-main-srv)
;; 	    (let* ((srv-addr (server-address the-srv)) ;; need serv
;; 		   (ipaddr   (alist-ref 'ipaddr  the-srv))
;; 		   (port     (alist-ref 'port    the-srv))
;; 		   (srvkey   (alist-ref 'servkey the-srv))
;; 		   (fullpath (db:dbname->path apath dbname))
;; 		   
;; 		   (new-the-srv (make-conndat
;; 				 apath:   apath
;; 				 dbname:  dbname
;; 				 fullname: fullpath
;; 				 hostport: srv-addr
;; 				 ;; socket: (open-nn-connection srv-addr)  - TODO - open ulex connection?
;; 				 ipaddr: ipaddr
;; 				 port: port
;; 				 srvpkt: the-srv
;; 				 srvkey: srvkey ;; generated by rmt:get-signature on the server side
;; 				 lastmsg: (current-seconds)
;; 				 expires: (+ (current-seconds)
;; 					     (server:expiration-timeout)
;; 					     -2) ;; this needs to be gathered during the ping
;; 				 )))
;; 	      (hash-table-set! conns fullpath new-the-srv)))
;; 	#t)))))
;; 
;; ;; NB// sinfo is a servdat struct
;; ;;
;; (define (rmt:general-open-connection sinfo apath dbname #!key (num-tries 5))
;;   (assert (not (equal? dbname ".db/main.db")) "ERROR: general-open-connection should never be called with main as the db")
;;   (let* ((mdbname  ".db/main.db") ;; (db:run-id->dbname #f)) TODO: put this back to the lookup when stable
;; 	 (fullname (db:dbname->path apath dbname))
;; 	 (conns    (servdat-conns sinfo))
;; 	 (mconn    (rmt:get-conn sinfo apath ".db/main.db"))
;; 	 (dconn    (rmt:get-conn sinfo apath dbname)))
;;     #;(if (and mconn
;; 	     (not (debug:print-logger)))
;; 	(begin
;; 	  (debug:print-info 0 *default-log-port* "Turning on logging to main, look in logs dir for main log.")
;; 	  (debug:print-logger rmt:log-to-main)))
;;     (cond
;;      ((and mconn
;; 	   dconn
;; 	   (< (current-seconds)(conndat-expires dconn)))
;;       #t) ;; good to go
;;      ((not mconn) ;; no channel open to main? open it...
;;       (rmt:open-main-connection sinfo apath)
;;       (rmt:general-open-connection sinfo apath dbname num-tries: (- num-tries 1)))
;;      ((not dconn)                 ;; no channel open to dbname?     
;;       (let* ((res (rmt:send-receive-real sinfo apath mdbname 'get-server `(,apath ,dbname))))
;; 	(case res
;; 	  ((server-started)
;; 	   (if (> num-tries 0)
;; 	       (begin
;; 		 (thread-sleep! 2)
;; 		 (rmt:general-open-connection sinfo apath dbname num-tries: (- num-tries 1)))
;; 	       (begin
;; 		 (debug:print-error 0 *default-log-port* "Failed to start servers needed or open channel to "apath", "dbname)
;; 		 (exit 1))))
;; 	  (else
;; 	   (if (list? res) ;; server has been registered and the info was returned. pass it on.
;; 	       (begin ;;  ("192.168.0.9" 53817
;; 		      ;;  "5e34239f48e8973b3813221e54701a01" "24310"
;; 		      ;;  "192.168.0.9"
;; 		      ;;  "/home/matt/data/megatest/tests/simplerun"
;; 		 ;;  ".db/1.db")
;; 		 (match
;; 		  res
;; 		  ((host port servkey pid ipaddr apath dbname)
;; 		   (debug:print-info 0 *default-log-port* "got "res)
;; 		   (hash-table-set! conns
;; 				    fullname
;; 				    (make-conndat
;; 				     apath: apath
;; 				     dbname: dbname
;; 				     hostport: (conc host":"port)
;; 				     ;; socket: (open-nn-connection (conc host":"port)) ;; TODO - open ulex connection?
;; 				     ipaddr: ipaddr
;; 				     port: port
;; 				     srvkey: servkey
;; 				     lastmsg: (current-seconds)
;; 				     expires: (+ (current-seconds)
;; 						 (server:expiration-timeout)
;; 						 -2))))
;; 		  (else
;; 		   (debug:print-info 0 *default-log-port* "return data from starting server did not match host port servkey pid ipaddr apath dbname " res)))
;; 		 res)
;; 	       (begin
;; 		 (debug:print-info 0 *default-log-port* "Unexpected result: " res)
;; 		 res)))))))
;;     #t))
;; 
;; ;;======================================================================
;; 
;; ;; FOR DEBUGGING SET TO #t
;; ;; (define *localmode* #t)
;; (define *localmode* #f)
(define *dbstruct* (make-dbr:dbstruct))
 
;; Defaults to current area
;;
(define (rmt:send-receive cmd rid params #!key (attemptnum 1)(area-dat #f))
  (let* ((apath      *toppath*)
	 (dbname     (db:run-id->dbname rid)))
	(api:execute-requests *dbstruct* cmd params)))

;; ;; db is at apath/.db/dbname, rid is an intermediary solution and will be removed
;; ;; sometime in the future
;; ;;
;; (define (rmt:send-receive-real sinfo apath dbname cmd params)
;;   (assert (not (eq? 'primordial (thread-name (current-thread)))) "FATAL: Do not call rmt:send-receive-real in the primodial thread.")
;;   (let* ((cdat (rmt:get-conn sinfo apath dbname)))
;;     (assert cdat "FATAL: rmt:send-receive-real called without the needed channels opened")
;;     (let* ((uconn    (servdat-uconn sinfo)) ;; get the interface to ulex
;; 	   ;; then send-receive using the ulex layer to host-port stored in cdat
;; 	   (res      (send-receive uconn (conndat-hostport cdat) cmd params))
;; 	   #;(th1      (make-thread (lambda ()
;; 				    (set! res (send-receive uconn (conndat-hostport cdat) cmd params)))
;; 				  "send-receive thread")))
;;       ;; (thread-start! th1)
;;       ;; (thread-join! th1)   ;; gratuitious thread stuff is so that mailbox is not used in primordial thead
;;       ;; since we accessed the server we can bump the expires time up
;;       (conndat-expires-set! cdat (+ (current-seconds)
;; 				    (server:expiration-timeout)
;; 				    -2)) ;; two second margin for network time misalignments etc.
;;       res)))
;; 
;; db is at apath/.db/dbname, rid is an intermediary solution and will be removed
;; sometime in the future.
;;
;; Purpose - call the main.db server and request a server be started
;; for the given area path and dbname
;;

(define (rmt:print-db-stats)
  (let ((fmtstr "~40a~7-d~9-d~20,2-f")) ;; "~20,2-f"
    (debug:print 18 *default-log-port* "DB Stats, "(seconds->year-week/day-time (current-seconds))"\n=====================")
    (debug:print 18 *default-log-port* (format #f "~40a~8a~10a~10a" "Cmd" "Count" "TotTime" "Avg"))
    (for-each (lambda (cmd)
		(let ((cmd-dat (hash-table-ref *db-stats* cmd)))
		  (debug:print 18 *default-log-port* (format #f fmtstr cmd (vector-ref cmd-dat 0) (vector-ref cmd-dat 1) (/ (vector-ref cmd-dat 1)(vector-ref cmd-dat 0))))))
	      (sort (hash-table-keys *db-stats*)
		    (lambda (a b)
		      (> (vector-ref (hash-table-ref *db-stats* a) 0)
			 (vector-ref (hash-table-ref *db-stats* b) 0)))))))

(define (rmt:get-max-query-average run-id)
  (mutex-lock! *db-stats-mutex*)
  (let* ((runkey (conc "run-id=" run-id " "))
	 (cmds   (filter (lambda (x)
			   (substring-index runkey x))
			 (hash-table-keys *db-stats*)))
	 (res    (if (null? cmds)
		     (cons 'none 0)
		     (let loop ((cmd (car cmds))
				(tal (cdr cmds))
				(max-cmd (car cmds))
				(res 0))
		       (let* ((cmd-dat (hash-table-ref *db-stats* cmd))
			      (tot     (vector-ref cmd-dat 0))
			      (curravg (/ (vector-ref cmd-dat 1) (vector-ref cmd-dat 0))) ;; count is never zero by construction
			      (currmax (max res curravg))
			      (newmax-cmd (if (> curravg res) cmd max-cmd)))
			 (if (null? tal)
			     (if (> tot 10)
				 (cons newmax-cmd currmax)
				 (cons 'none 0))
			     (loop (car tal)(cdr tal) newmax-cmd currmax)))))))
    (mutex-unlock! *db-stats-mutex*)
    res))

;; ;; host and port are used to ensure we are remove proper records
;; (define (rmt:server-shutdown host port)
;;   (let ((dbfile   (servdat-dbfile *db-serv-info*)))
;;     (debug:print-info 0 *default-log-port* "dbfile is "dbfile)
;;     (if dbfile
;; 	(let* ((am-server  (args:get-arg "-server"))
;; 	       (dbfile     (args:get-arg "-db"))
;; 	       (apath      *toppath*)
;; 	       #;(sinfo     *remotedat*)) ;; foundation for future fix
;; 	  (if *dbstruct-db*
;; 	      (let* ((dbdat      (db:get-dbdat *dbstruct-db* apath dbfile))
;; 		     (db         (dbr:dbdat-db dbdat))
;; 		     (inmem      (dbr:dbdat-db dbdat))   ;; WRONG
;; 		     )
;; 		;; do a final sync here
;; 		(debug:print-info 0 *default-log-port* "Doing final sync for "apath" "dbfile" at "(current-seconds))
;; 		(db:sync-inmem->disk *dbstruct-db* apath dbfile force-sync: #t)
;; 		;; let's finalize here
;; 		(debug:print-info 0 *default-log-port* "Finalizing db and inmem")
;; 		(if (sqlite3:database? db)
;; 		    (sqlite3:finalize! db)
;; 		    (debug:print-info 0 *default-log-port* "in rmt:server-shutdown, db is not a database, not finalizing..."))
;; 		(if (sqlite3:database? inmem)
;; 		    (sqlite3:finalize! inmem)
;; 		    (debug:print-info 0 *default-log-port* "in rmt:server-shutdown, inmem is not a database, not finalizing..."))
;; 		(debug:print-info 0 *default-log-port* "Finalizing db and inmem complete"))
;; 	      (debug:print-info 0 *default-log-port* "Db was never opened, no cleanup to do."))
;; 	  (if (not am-server)
;; 	      (debug:print-info 0 *default-log-port* "I am not a server, should NOT get here!")
;; 	      (if (string-match ".*/main.db$" dbfile)
;; 		  (let ((pkt-file (conc (get-pkts-dir *toppath*)
;; 					"/" (servdat-uuid *db-serv-info*)
;; 					".pkt")))
;; 		    (debug:print-info 0 *default-log-port* "removing pkt "pkt-file)
;; 		    (delete-file* pkt-file)
;; 		    (debug:print-info 0 *default-log-port* "Releasing lock (if any) for "dbfile ", host "host", port "port)
;; 		    (db:with-lock-db
;; 		     (servdat-dbfile *db-serv-info*)
;; 		     (lambda (dbh dbfile)
;; 		       (db:release-lock dbh dbfile host port)))) ;; I'm not the server - should not have a lock to remove
;; 		  (let* ((sdat *db-serv-info*) ;; we have a run-id server
;; 			 (host (servdat-host sdat))
;; 			 (port (servdat-port sdat))
;; 			 (uuid (servdat-uuid sdat))
;; 			 (res  (rmt:deregister-server *db-serv-info* *toppath* host port uuid dbfile)))
;; 		    (debug:print-info 0 *default-log-port* "deregistered-server, res="res)
;; 		    (debug:print-info 0 *default-log-port* "deregistering server "host":"port" with uuid "uuid)
;; 		    )))))))
;; 
;; 
;; (define (common:run-sync?)
;;     ;; (and (common:on-homehost?)
;;   (args:get-arg "-server"))
;; 
;; (define *rmt:run-mutex* (make-mutex))
;; (define *rmt:run-flag* #f)
;; 
;; ;; Main entry point to start a server. was start-server
;; (define (rmt:run hostn)
;;   (mutex-lock! *rmt:run-mutex*)
;;   (if *rmt:run-flag*
;;       (begin
;; 	(debug:print-warn 0 *default-log-port* "rmt:run already running.")
;; 	(mutex-unlock! *rmt:run-mutex*))
;;       (begin
;; 	(set! *rmt:run-flag* #t)
;; 	(mutex-unlock! *rmt:run-mutex*)
;; 	;;  ;; Configurations for server
;; 	;;  (tcp-buffer-size 2048)
;; 	;;  (max-connections 2048) 
;; 	(debug:print 2 *default-log-port* "PID: "(current-process-id)". Attempting to start the server ...")
;; 	(if (and *db-serv-info*
;; 		 (servdat-uconn *db-serv-info*))
;; 	    (let* ((uconn (servdat-uconn *db-serv-info*)))
;; 	      (wait-and-close uconn))
;; 	    (let* ((port            (portlogger:open-run-close portlogger:find-port))
;; 		   (handler-proc    (lambda (rem-host-port qrykey cmd params) ;;
;; 				      (set! *db-last-access* (current-seconds))
;; 				      (assert (list? params) "FATAL: handler called with non-list params")
;; 				      (assert (args:get-arg "-server") "FATAL: handler called on non-server side. cmd="cmd", params="params)
;; 				      (debug:print 0 *default-log-port* "handler call: "cmd", params="params)
;; 				      (api:execute-requests *dbstruct-db* cmd params))))
;; 	      ;; (api:process-request *dbstuct-db* 
;; 	      (if (not *db-serv-info*)
;; 		  (set! *db-serv-info* (make-servdat host: hostn port: port)))
;; 	      (let* ((uconn (run-listener handler-proc port))
;; 		     (rport (udat-port uconn))) ;; the real port
;; 		(servdat-host-set! *db-serv-info* hostn)
;; 		(servdat-port-set! *db-serv-info* rport)
;; 		(servdat-uconn-set! *db-serv-info* uconn)
;; 		(wait-and-close uconn)
;; 		(db:print-current-query-stats)
;; 		)))
;; 	(let* ((host (servdat-host *db-serv-info*))
;; 	       (port (servdat-port *db-serv-info*))
;; 	       (mode (or (servdat-mode *db-serv-info*)
;; 			 "non-db")))
;; 	  ;; server exit stuff here
;; 	  ;; (rmt:server-shutdown host port) - always do in on-exit
;; 	  ;; (portlogger:open-run-close portlogger:set-port port "released") ;; moved to on-exit 
;; 	  (debug:print-info 0 *default-log-port* "Server "host":"port" mode "mode"shutdown complete. Exiting")
;; 	  ))))
;; 
;; ;;======================================================================
;; ;; S E R V E R   U T I L I T I E S 
;; ;;======================================================================
;; 
;; 
;; ;;======================================================================
;; ;; NEW SERVER METHOD
;; ;;======================================================================
;; 
;; ;; only use for main.db - need to re-write some of this :(
;; ;;
;; (define (get-lock-db sdat dbfile host port)
;;   (assert host "FATAL: get-lock-db called with host not set.")
;;   (assert port "FATAL: get-lock-db called with port not set.")
;;   (let* ((dbh (db:open-run-db dbfile db:initialize-db)) ;; open-run-db creates a standard db with schema used by all situations
;; 	 (res (db:get-iam-server-lock dbh dbfile host port))
;; 	 (uconn (servdat-uconn sdat)))
;;     ;; res => list then already locked, check server is responsive
;;     ;;     => #t then sucessfully got the lock
;;     ;;     => #f reserved for future use as to indicate something went wrong
;;     (match res
;;       ((owner_pid owner_host owner_port event_time)
;;        (if (server-ready? uconn (conc owner_host":"owner_port) "abc")
;; 	   #f      ;; locked by someone else
;; 	   (begin  ;; locked by someone dead and gone
;; 	     (debug:print 0 *default-log-port* "WARNING: stale lock - have to steal it. This may fail.")
;; 	     (db:steal-lock-db dbh dbfile port))))
;;       (#t  #t) ;; placeholder so that we don't touch res if it is #t
;;       (else (set! res #f)))
;;     (sqlite3:finalize! dbh)
;;     res))
;; 
;; 
;; (define (register-server pkts-dir pkt-spec host port servkey ipaddr dbpath)
;;   (let* ((pkt-dat `((host    . ,host)
;; 		    (port    . ,port)
;; 		    (servkey . ,servkey)
;; 		    (pid     . ,(current-process-id))
;; 		    (ipaddr  . ,ipaddr)
;; 		    (dbpath  . ,dbpath)))
;; 	 (uuid    (write-alist->pkt
;; 		   pkts-dir
;; 		   pkt-dat
;; 		   pktspec: pkt-spec
;; 		   ptype: 'server)))
;;     (debug:print 0 *default-log-port* "Server on "host":"port" registered in pkt "uuid)
;;     uuid))
;; 
;; (define (get-pkts-dir #!optional (apath #f))
;;   (let* ((effective-toppath (or *toppath* apath)))
;;     (assert effective-toppath
;; 	    "ERROR: get-pkts-dir called without *toppath* set. Exiting.")
;;     (let* ((pdir (conc effective-toppath "/.meta/srvpkts")))
;;       (if (file-exists? pdir)
;; 	  pdir
;; 	  (begin
;; 	    (handle-exceptions ;; this exception handler should NOT be needed but ...
;; 		exn
;; 		pdir
;; 	      (create-directory pdir #t))
;; 	    pdir)))))
;; 
;; ;; given a pkts dir read 
;; ;;
;; (define (get-all-server-pkts pktsdir-in pktspec)
;;   (let* ((pktsdir  (if (file-exists? pktsdir-in)
;; 		       pktsdir-in
;; 		       (begin
;; 			 (create-directory pktsdir-in #t)
;; 			 pktsdir-in)))
;; 	 (all-pkt-files (glob (conc pktsdir "/*.pkt"))))
;;     (map (lambda (pkt-file)
;; 	   (read-pkt->alist pkt-file pktspec: pktspec))
;; 	 all-pkt-files)))
;; 
;; (define (server-address srv-pkt)
;;   (conc (alist-ref 'host srv-pkt) ":"
;; 	(alist-ref 'port srv-pkt)))
	
(define (server-ready? uconn host-port key) ;; server-address is host:port
  #;(let* ((params `((cmd . ping)(key . ,key)))
	 (data `((cmd . ping)
		 (key . ,key)
		 (params . ,params))) ;; I don't get it.
	 (res  (send-receive uconn host-port 'ping data)))
    (if (eq? res 'ack) ;; yep, likely it is who we want on the other end
	res
  #f))
  #t)

;; ; from the pkts return servers associated with dbpath
;; ;; NOTE: Only one can be alive - have to check on each
;; ;;       in the list of pkts returned
;; ;;
;; (define (get-viable-servers serv-pkts dbpath)
;;   (let loop ((tail serv-pkts)
;; 	     (res  '()))
;;     (if (null? tail)
;; 	res ;; NOTE: sort by age so oldest is considered first
;; 	(let* ((spkt (car tail)))
;; 	  (loop (cdr tail)
;; 		(if (equal? dbpath (alist-ref 'dbpath spkt))
;; 		    (cons spkt res)
;; 		    res))))))
;; 
;; (define (remove-pkts-if-not-alive uconn serv-pkts)
;;   (filter (lambda (pkt)
;; 	    (let* ((host (alist-ref 'host pkt))
;; 		   (port (alist-ref 'port pkt))
;; 		   (host-port (conc host":"port))
;; 		   (key  (alist-ref 'servkey  pkt))
;; 		   (pktz (alist-ref 'Z        pkt))
;; 		   (res  (server-ready? uconn host-port key)))
;; 	      (if res
;; 		  res
;; 		  (let* ((pktsdir (get-pkts-dir *toppath*))
;; 			 (pktpath (conc pktsdir"/"pktz".pkt")))
;; 		    (debug:print 0 *default-log-port* "WARNING: pkt with no server "pktpath)
;; 		    (delete-file* pktpath)
;; 		    #f))))
;; 	  serv-pkts))
;; 
;; ;; from viable servers get one that is alive and ready
;; ;;
;; (define (get-the-server uconn apath serv-pkts)
;;   (let loop ((tail serv-pkts))
;;     (if (null? tail)
;; 	#f
;; 	(let* ((spkt  (car tail))
;; 	       (host  (alist-ref 'ipaddr spkt))
;; 	       (port  (alist-ref 'port spkt))
;; 	       (host-port (conc host":"port))
;; 	       (dbpth (alist-ref 'dbpath spkt))
;; 	       (srvkey (alist-ref 'Z spkt)) ;; (alist-ref 'srvkey spkt))
;; 	       (addr  (server-address spkt)))
;; 	  (if (server-ready? uconn host-port srvkey)
;; 	      spkt
;; 	      (loop (cdr tail)))))))
;; 
;; ;; am I the "first" in line server? I.e. my D card is smallest
;; ;; use Z card as tie breaker
;; ;;
;; (define (get-best-candidate serv-pkts dbpath)
;;   (if (null? serv-pkts)
;;       #f
;;       (let loop ((tail serv-pkts)
;; 		 (best  (car serv-pkts)))
;; 	(if (null? tail)
;; 	    best
;; 	    (let* ((candidate (car tail))
;; 		   (candidate-bd (string->number (alist-ref 'D candidate)))
;; 		   (best-bd      (string->number (alist-ref 'D best)))
;; 		   ;; bigger number is younger
;; 		   (candidate-z  (alist-ref 'Z candidate))
;; 		   (best-z       (alist-ref 'Z best))
;; 		   (new-best     (cond
;; 				  ((> best-bd candidate-bd) ;; best is younger than candidate
;; 				   candidate)
;; 				  ((< best-bd candidate-bd) ;; candidate is younger than best
;; 				   best)
;; 				  (else
;; 				   (if (string>=? best-z candidate-z)
;; 				       best
;; 				       candidate))))) ;; use Z card as tie breaker
;; 	      (if (null? tail)
;; 		  new-best
;; 		  (loop (cdr tail) new-best)))))))
;; 	  
;; 
;; ;;======================================================================
;; ;; END NEW SERVER METHOD
;; ;;======================================================================
;; 
;; ;; if .db/main.db check the pkts
;; ;; 
;; (define (rmt:wait-for-server pkts-dir db-file server-key)
;;   (let* ((sdat *db-serv-info*))
;;     (let loop ((start-time (current-seconds))
;; 	       (changed    #t)
;; 	       (last-sdat  "not this"))
;;       (begin ;; let ((sdat #f))
;; 	(thread-sleep! 0.01)
;; 	(debug:print-info 0 *default-log-port* "Waiting for server alive signature")
;; 	(mutex-lock! *heartbeat-mutex*)
;; 	(set! sdat *db-serv-info*)
;; 	(mutex-unlock! *heartbeat-mutex*)
;; 	(if (and sdat
;; 		 (not changed)
;; 		 (> (- (current-seconds) start-time) 2))
;; 	    (let* ((uconn (servdat-uconn sdat)))
;; 	      (servdat-status-set! sdat 'iface-stable)
;; 	      (debug:print-info 0 *default-log-port* "Received server alive signature, now attempting to lock in server")
;; 	      ;; create a server pkt in *toppath*/.meta/srvpkts
;; 	      
;; 	      ;; TODO:
;; 	      ;;   1. change sdat to stuct
;; 	      ;;   2. add uuid to struct
;; 	      ;;   3. update uuid in sdat here
;; 	      ;;
;; 	      (servdat-uuid-set! sdat
;; 				 (register-server
;; 				  pkts-dir *srvpktspec*
;; 				  (get-host-name)
;; 				  (servdat-port sdat) server-key
;; 				  (servdat-host sdat) db-file))
;; 	      ;; (set! *my-signature* (servdat-uuid sdat)) ;; replace with Z, no, stick with proper key
;; 	      ;; now read pkts and see if we are a contender
;; 	      (let* ((all-pkts     (get-all-server-pkts pkts-dir *srvpktspec*))
;; 		     (viables      (get-viable-servers all-pkts db-file))
;; 		     (alive        (remove-pkts-if-not-alive uconn viables))
;; 		     (best-srv     (get-best-candidate alive db-file))
;; 		     (best-srv-key (if best-srv (alist-ref 'servkey best-srv) #f))
;; 		     (i-am-srv     (equal? best-srv-key server-key))
;; 		     (delete-pkt   (lambda ()
;; 				     (let* ((pktfile (conc (get-pkts-dir *toppath*)
;; 							 "/" (servdat-uuid *db-serv-info*)
;; 							 ".pkt")))
;; 				       (debug:print-info 0 *default-log-port* "Attempting to remove bogus pkt file "pktfile)
;; 				       (delete-file* pktfile))))) ;; remove immediately instead of waiting for on-exit
;; 		(debug:print 0 *default-log-port* "best-srv-key: "best-srv-key", server-key: "server-key", i-am-srv: "i-am-srv)
;; 		;; am I the best-srv, compare server-keys to know
;; 		(if i-am-srv
;; 		    (if (get-lock-db sdat db-file (servdat-host sdat)(servdat-port sdat)) ;; (db:get-iam-server-lock *dbstruct-db* *toppath* run-id)
;; 			(begin
;; 			  (debug:print-info 0 *default-log-port* "I'm the server!")
;; 			  (servdat-dbfile-set! sdat db-file)
;; 			  (servdat-status-set! sdat 'db-locked))
;; 			(begin
;; 			  (debug:print-info 0 *default-log-port* "I'm not the server, exiting.")
;; 			  (bdat-time-to-exit-set! *bdat* #t)
;; 			  (delete-pkt)
;; 			  (thread-sleep! 0.2)
;; 			  (exit)))
;; 		    (begin
;; 		      (debug:print-info 0 *default-log-port*
;; 				   "Keys do not match "best-srv-key", "server-key", exiting.")
;; 		      (bdat-time-to-exit-set! *bdat* #t)
;; 		      (delete-pkt)
;; 		      (thread-sleep! 0.2)
;; 		      (exit)))
;; 		sdat))
;; 	    (begin ;; sdat not yet contains server info
;; 	      (debug:print-info 0 *default-log-port* "Still waiting, last-sdat=" last-sdat)
;; 	      (sleep 4)
;; 	      (if (> (- (current-seconds) start-time) 120) ;; been waiting for two minutes
;; 		  (begin
;; 		    (debug:print-error 0 *default-log-port* "transport appears to have died, exiting server")
;; 		    (exit))
;; 		  (loop start-time
;; 			(equal? sdat last-sdat)
;; 			sdat))))))))
;; 
;; (define (rmt:register-server sinfo apath iface port server-key dbname)
;;   (servdat-conns sinfo) ;; just checking types
;;   (rmt:open-main-connection sinfo apath) ;; we need a channel to main.db
;;   (rmt:send-receive-real sinfo apath      ;; params: host port servkey pid ipaddr dbpath
;; 			 (db:run-id->dbname #f)
;; 			 'register-server `(,iface
;; 					    ,port
;; 					    ,server-key
;; 					    ,(current-process-id)
;; 					    ,iface
;; 					    ,apath
;; 					    ,dbname)))
;; 
;; (define (rmt:get-count-servers sinfo apath)
;;   (servdat-conns sinfo) ;; just checking types
;;   (rmt:open-main-connection sinfo apath) ;; we need a channel to main.db
;;   (rmt:send-receive-real sinfo apath      ;; params: host port servkey pid ipaddr dbpath
;; 			 (db:run-id->dbname #f)
;; 			 'get-count-servers `(,apath)))

(define (rmt:get-servers-info apath)
  (rmt:send-receive 'get-servers-info #f `(,apath)))

;; (define (rmt:deregister-server db-serv-info apath iface port server-key dbname)
;;   (rmt:open-main-connection db-serv-info apath) ;; we need a channel to main.db
;;   (rmt:send-receive-real db-serv-info apath      ;; params: host port servkey pid ipaddr dbpath
;;                          (db:run-id->dbname #f)
;;                          'deregister-server `(,iface
;;                                               ,port
;;                                               ,server-key
;;                                               ,(current-process-id)
;;                                               ,iface
;;                                               ,apath
;;                                               ,dbname)))
;; 
;; (define (rmt:wait-for-stable-interface #!optional (num-tries-allowed 100))
;;   ;; wait until *db-serv-info* stops changing
;;   (let* ((stime (current-seconds)))
;;     (let loop ((last-host  #f)
;; 	       (last-port  #f)
;; 	       (tries 0))
;;       (let* ((curr-host (and *db-serv-info* (servdat-host *db-serv-info*)))
;; 	     (curr-port (and *db-serv-info* (servdat-port *db-serv-info*))))
;; 	;; first we verify port and interface, update *db-serv-info* in need be.
;; 	(cond
;; 	 ((> tries num-tries-allowed)
;; 	  (debug:print 0 *default-log-port* "rmt:keep-running, giving up after trying for several minutes.")
;; 	  (exit 1))
;; 	 ((not *db-serv-info*)
;; 	  (thread-sleep! 0.25)
;; 	  (loop curr-host curr-port (+ tries 1)))
;; 	 ((or (not last-host)(not last-port))
;; 	  (debug:print 0 *default-log-port* "rmt:keep-running, still no interface, tries="tries)
;; 	  (thread-sleep! 0.25)
;; 	  (loop curr-host curr-port (+ tries 1)))
;; 	 ((or (not (equal? last-host curr-host))
;; 	      (not (equal? last-port curr-port)))
;; 	  (debug:print-info 0 *default-log-port* "WARNING: interface changed, refreshing iface and port info")
;; 	  (thread-sleep! 0.25)
;; 	  (loop curr-host curr-port (+ tries 1)))
;; 	 ((< (- (current-seconds) stime) 1) ;; keep up the looping until at least 3 seconds have passed
;; 	  (thread-sleep! 0.5)
;; 	  (loop curr-host curr-port (+ tries 1)))
;; 	 (else
;; 	  (rmt:get-signature) ;; sets *my-signature* as side effect
;; 	  (servdat-status-set! *db-serv-info* 'interface-stable)
;; 	  (debug:print 0 *default-log-port*
;; 		       "SERVER STARTED: " curr-host
;; 		       ":" curr-port
;; 		       " AT " (current-seconds) " server signature: " *my-signature*
;; 		       " with "(servdat-trynum *db-serv-info*)" port changes")
;; 	  (flush-output *default-log-port*)
;; 	  #t))))))
;; 
;; ;; run rmt:keep-running in a parallel thread to monitor that the db is being 
;; ;; used and to shutdown after sometime if it is not.
;; ;;
;; (define (rmt:keep-running dbname) 
;;   ;; if none running or if > 20 seconds since 
;;   ;; server last used then start shutdown
;;   ;; This thread waits for the server to come alive
;;   (debug:print-info 0 *default-log-port* "Starting the sync-back, keep alive thread in server")
;; 
;;   (let* ((sinfo             *db-serv-info*)
;; 	 (server-start-time (current-seconds))
;; 	 (pkts-dir          (get-pkts-dir))
;; 	 (server-key        (rmt:get-signature)) ;; This servers key
;; 	 (is-main           (equal? (args:get-arg "-db") ".db/main.db"))
;; 	 (last-access       0)
;; 	 (server-timeout    (server:expiration-timeout))
;; 	 (shutdown-server-sequence (lambda (host port)
;; 				     (set! *unclean-shutdown* #f) ;; Should not be needed anymore
;; 				     (debug:print-info 0 *default-log-port* "Starting to shutdown the server. pid="(current-process-id))
;; 				     ;; (rmt:server-shutdown host port) -- called in on-exit
;; 				     ;; (portlogger:open-run-close portlogger:set-port port "released") called in on-exit
;; 				     (exit)))
;; 	 (timed-out?        (lambda ()
;; 			      (<= (+ last-access server-timeout)
;; 				  (current-seconds)))))
;;     (servdat-dbfile-set! *db-serv-info* (args:get-arg "-db"))
;;     ;; main and run db servers have both got wait logic (could/should merge it)
;;     (if is-main
;; 	(rmt:wait-for-server pkts-dir dbname server-key)
;; 	(rmt:wait-for-stable-interface))
;;     ;; this is our forever loop
;;     (let* ((iface (servdat-host *db-serv-info*))
;; 	   (port  (servdat-port *db-serv-info*))
;; 	   (uconn (servdat-uconn *db-serv-info*)))
;;       (let loop ((count          0)
;; 		 (bad-sync-count 0)
;; 		 (start-time     (current-milliseconds)))
;; 	(if (and (not is-main)
;; 		 (common:low-noise-print 60 "servdat-status"))
;; 	    (debug:print-info 0 *default-log-port* "servdat-status is " (servdat-status *db-serv-info*)))
;; 
;; 	(mutex-lock! *heartbeat-mutex*)
;; 	;; set up the database handle
;; 	(if (not *dbstruct-db*) ;; no db opened yet, open the db and register with main if appropriate
;; 	      (let ((watchdog (bdat-watchdog *bdat*)))
;; 		(debug:print 0 *default-log-port* "SERVER: dbprep")
;; 		(db:setup dbname) ;; sets *dbstruct-db* as side effect
;; 		(servdat-status-set! *db-serv-info* 'db-opened)
;; 		;; IFF I'm not main, call into main and register self
;; 		(if (not is-main)
;; 		    (let ((res (rmt:register-server sinfo
;; 						    *toppath* iface port
;; 						    server-key dbname)))
;; 		      (if res ;; we are the server
;; 			  (servdat-status-set! *db-serv-info* 'have-interface-and-db)
;; 			  ;; now check that the db locker is alive, clear it out if not
;; 			  (let* ((serv-info (rmt:server-info *toppath* dbname)))
;; 			    (match serv-info
;; 				   ((host port servkey pid ipaddr apath dbpath)
;; 				    (if (not (server-ready? uconn (conc host":"port) servkey))
;; 					(begin
;; 					  (debug:print-info 0 *default-log-port* "Server registered but not alive. Removing and trying again.")
;; 					  (rmt:deregister-server sinfo apath host port servkey dbpath) ;; servkey pid ipaddr apath dbpath)
;; 					  (loop (+ count 1) bad-sync-count start-time))))
;; 				   (else
;; 				    (debug:print 0 *default-log-port* "We are not the server for "dbname", exiting. Server info is: "serv-info)
;; 				    (exit)))))))
;; 		(debug:print 0 *default-log-port*
;; 			     "SERVER: running, db "dbname" opened, megatest version: "
;; 			   (common:get-full-version))
;; 	      ;; start the watchdog
;; 
;; 	      ;; is this really needed?
;; 	      
;; 	      #;(if watchdog
;; 		  (if (not (member (thread-state watchdog)
;; 				   '(ready running blocked
;; 					   sleeping dead)))
;; 		      (begin
;; 			(debug:print-info 0 *default-log-port* "Starting watchdog thread (in state "(thread-state watchdog)")")
;; 			(thread-start! watchdog))
;; 		      (debug:print-info 0 *default-log-port* "Not starting watchdog thread (in state "(thread-state watchdog)")"))
;; 		  (debug:print 0 *default-log-port* "ERROR: *watchdog* not setup, cannot start it."))
;; 	      #;(loop (+ count 1) bad-sync-count start-time)
;; 	      ))
;; 	
;; 	(db:sync-inmem->disk *dbstruct-db* *toppath* dbname force-sync: #t)
;; 	
;; 	(mutex-unlock! *heartbeat-mutex*)
;; 	
;; 	;; when things go wrong we don't want to be doing the various
;; 	;; queries too often so we strive to run this stuff only every
;; 	;; four seconds or so.
;; 	(let* ((sync-time (- (current-milliseconds) start-time))
;; 	       (rem-time  (quotient (- 4000 sync-time) 1000)))
;; 	  (if (and (<= rem-time 4)
;; 		   (>  rem-time 0))
;; 	      (thread-sleep! rem-time)))
;;     
;; 	;; Transfer *db-last-access* to last-access to use in checking that we are still alive
;; 	(set! last-access *db-last-access*)
;; 	
;; 	(if (< count 1) ;; 3x3 = 9 secs aprox
;; 	    (loop (+ count 1) bad-sync-count (current-milliseconds)))
;; 	
;; 	(if (common:low-noise-print 60 "dbstats")
;; 	    (begin
;; 	      (debug:print 0 *default-log-port* "Server stats:")
;; 	      (db:print-current-query-stats)))
;; 	(let* ((hrs-since-start  (/ (- (current-seconds) server-start-time) 3600)))
;; 	  (cond
;; 	   ((not *server-run*)
;; 	    (debug:print-info 0 *default-log-port* "*server-run* set to #f. Shutting down.")
;; 	    (shutdown-server-sequence (get-host-name) port))
;; 	   ((timed-out?)
;; 	    (debug:print-info 0 *default-log-port* "Server timed out. seconds since last db access: " (- (current-seconds) last-access))
;; 	    (shutdown-server-sequence (get-host-name) port))
;; 	   ((and *server-run*
;; 		 (or (not (timed-out?))
;; 		     (if is-main ;; do not exit if there are other servers (keep main open until all others gone)
;; 			 (> (rmt:get-count-servers sinfo *toppath*) 1)
;; 			 #f)))
;; 	    (if (common:low-noise-print 120 "server continuing")
;; 		(debug:print-info 0 *default-log-port* "Server continuing, seconds since last db access: " (- (current-seconds) last-access)))
;; 	    (loop 0 bad-sync-count (current-milliseconds)))
;; 	   (else
;; 	    (set! *unclean-shutdown* #f)
;; 	    (debug:print-info 0 *default-log-port* "Server timed out. seconds since last db access: " (- (current-seconds) last-access))
;; 	    (shutdown-server-sequence (get-host-name) port)
;; 	    #;(debug:print-info 0 *default-log-port* "Sending 'quit to server, received: "
;; 			      (open-send-receive-nn (conc iface":"port)      ;; do this here and not in server-shutdown
;; 						    (sexpr->string 'quit))))))))))
;; 
;; (define (rmt:get-reasonable-hostname)
;;   (let* ((inhost (or (args:get-arg "-server") "-")))
;;     (if (equal? inhost "-")
;; 	(get-host-name)
;; 	inhost)))
;; 
;; Call this to start the actual server
;;
;; all routes though here end in exit ...
;;
;; This is the point at which servers are started
;;
(define (rmt:server-launch dbname)
  (debug:print-info 0 *default-log-port* "Entered rmt:server-launch")
  #;(let* ((th2 (make-thread (lambda ()
			     (debug:print-info 0 *default-log-port* "Server run thread started")
			     (rmt:run (rmt:get-reasonable-hostname)))
			   "Server run"))
	 (th3 (make-thread (lambda ()
			     (debug:print-info 0 *default-log-port* "Server monitor thread started")
			     (if (args:get-arg "-server")
				 (rmt:keep-running dbname)))
			     "Keep running")))
    (thread-start! th2)
    (thread-sleep! 0.252) ;; give the server time to settle before starting the keep-running monitor.
    (thread-start! th3)
    (set! *didsomething* #t)
    (thread-join! th2)
    (thread-join! th3))
  #f)
;; 	    
;; ;;======================================================================
;; ;;  S E R V E R   -  D I R E C T   C A L L S
;; ;;======================================================================
;; 
;; (define (rmt:kill-server run-id)
;;   (rmt:send-receive 'kill-server #f (list run-id)))
;; 
;; (define (rmt:start-server run-id)
;;   (rmt:send-receive 'start-server #f (list run-id)))
;; 
;; (define (rmt:server-info apath dbname)
;;   (rmt:send-receive 'get-server-info #f (list apath dbname)))
;; 
;; ;;======================================================================
;; ;; Nanomsg transport
;; ;;======================================================================
;; 
;; #;(define (is-port-in-use port-num)
;;   (let* ((ret #f))
;;     (let-values (((inp oup pid)
;; 		  (process "netstat" (list  "-tulpn" ))))
;;       (let loop ((inl (read-line inp)))
;;         (if (not (eof-object? inl))
;;             (begin 
;; 	      (if (string-search (regexp (conc ":" port-num)) inl)
;; 		  (begin
;; 					;(print "Output: "  inl)
;; 		    (set! ret  #t))
;; 		  (loop (read-line inp)))))))
;;     ret))
;; 
;; #;(define (open-nn-connection host-port)
;;   (let ((req  (make-req-socket))
;;         (uri  (conc "tcp://" host-port)))
;;     (nng-dial req uri)
;;     (socket-set! req 'nng/recvtimeo 2000)
;;     req))
;; 
;; #;(define (send-receive-nn req msg)
;;   (nng-send req msg)
;;   (nng-recv req))
;; 
;; #;(define (close-nn-connection req)
;;   (nng-close! req))
;;   
;; ;; ;; open connection to server, send message, close connection
;; ;; ;;
;; ;; (define (open-send-close-nn host-port msg #!key (timeout 3) ) ;; default timeout is 3 seconds
;; ;;   (let ((req  (make-req-socket 'req))
;; ;;         (uri  (conc "tcp://" host-port))
;; ;;         (res  #f)
;; ;;         ;; (contacts (alist-ref 'contact attrib))
;; ;;         ;; (mode (alist-ref 'mode attrib))
;; ;; 	)
;; ;;     (socket-set! req 'nng/recvtimeo 2000)
;; ;;     (handle-exceptions
;; ;;      exn
;; ;;      (let ((emsg ((condition-property-accessor 'exn 'message) exn)))
;; ;;        ;; Send notification       
;; ;;        (debug:print 0 *default-log-port* "ERROR: Failed to connect / send to " uri " message was \"" emsg "\"" )
;; ;;        #f)
;; ;;      (nng-dial req uri)
;; ;;      ;; (print "Connected to the server " )
;; ;;      (nng-send req msg)
;; ;;      ;; (print "Request Sent")  
;; ;;      (let* ((th1  (make-thread (lambda ()
;; ;;                                  (let ((resp (nng-recv req)))
;; ;;                                    (nng-close! req)
;; ;;                                    (set! res (if (equal? resp "ok")
;; ;;                                                  #t
;; ;;                                                  #f))))
;; ;;                                "recv thread"))
;; ;;             (th2 (make-thread (lambda ()
;; ;;                                 (thread-sleep! timeout)
;; ;;                                 (thread-terminate! th1))
;; ;; 			      "timer thread")))
;; ;;        (thread-start! th1)
;; ;;        (thread-start! th2)
;; ;;        (thread-join! th1)
;; ;;        res))))
;; ;; 
;; #;(define (open-send-receive-nn host-port msg #!key (timeout 3) ) ;; default timeout is 3 seconds
;;   (let ((req  (make-req-socket))
;;         (uri  (conc "tcp://" host-port))
;;         (res  #f)) 
;;     (handle-exceptions
;;      exn
;;      (let ((emsg ((condition-property-accessor 'exn 'message) exn)))
;;        ;; Send notification      
;;        (debug:print 0 *default-log-port* "ERROR: Failed to connect / send to " uri " message was \"" emsg "\", exn=" exn)
;;        #f)
;;      (nng-dial req uri)
;;      (nng-send req msg)
;;      (let* ((th1  (make-thread (lambda ()
;;                                  (let ((resp (nng-recv req)))
;;                                    (nng-close! req)
;;                                    ;; (print resp)
;;                                    (set! res resp)))
;;                                "recv thread"))
;;             (th2 (make-thread (lambda ()
;;                                 (thread-sleep! timeout)
;;                                 (thread-terminate! th1))
;;                              "timer thread")))
;;        (thread-start! th1)
;;        (thread-start! th2)
;;        (thread-join! th1)
;;        res))))
;; 
;; ;;======================================================================
;; ;; S E R V E R   U T I L I T I E S 
;; ;;======================================================================
;; 
;; ;; 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)))
;; 
;; ;; (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))))

)