Megatest

     mdb
     "SELECT id,server_id,pid,hostname,cmdline,login_time,logout_time FROM clients WHERE server_id=?;"
     server-id)))

(define (tasks:have-clients? mdb server-id)
  (null? (tasks:get-logged-in-clients mdb server-id)))

;; ping each server in the db and return first found that responds. 
;; remove any others. will not necessarily remove all!
(define (tasks:get-best-server mdb)
  (let ((res #f))
  (let ((res '())
	(best #f))
    (sqlite3:for-each-row
     (lambda (id hostname port)
       (set! res (list hostname port)))
       (set! res (cons (list hostname port) res))
       (debug:print-info 1 "Found " hostname ":" port))
     mdb
     "SELECT id,hostname,port FROM servers WHERE state='live' ORDER BY start_time DESC LIMIT 1;")
    (print "res=" res)
    (if (null? res) #f
	(let loop ((hed (car res))
    res))
		   (tal (cdr res)))
	  (print "hed=" hed ", tal=" tal)
	  (let* ((host (car hed))
		 (port (cadr hed))
		 (ping-res (server:ping host port)))
	    (if ping-res hed
		;; remove defunct server from table
		(begin
		  (open-run-close tasks:server-deregister tasks:open-db  host port: port)
		  (if (null? tal)
		      #f
		      (loop (car tal)(cdr tal))))))))))

(define (tasks:get-all-servers mdb)
  (let ((res '()))
    (sqlite3:for-each-row
     (lambda (id pid hostname port start-time priority state)
       (set! res (cons (vector id pid hostname port start-time priority state) res)))
     mdb