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Comment:Factor out http-transport aspect of rmt.scm in preparation for adding tcp-transport.scm
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Timelines: family | ancestors | descendants | both | v1.80-dbperf
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SHA1: bce6a00a7023f9a22d7456678d7b1fd4484a7657
User & Date: matt on 2023-02-10 09:48:25
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Context
2023-02-10
21:06
Merging pretty good branch v1.80-dbperf to v1.80 check-in: 7170e5f43b user: matt tags: v1.80
09:48
Factor out http-transport aspect of rmt.scm in preparation for adding tcp-transport.scm Closed-Leaf check-in: bce6a00a70 user: matt tags: v1.80-dbperf
2023-02-06
19:35
Squashed v1.80-dbperformance into one commit check-in: 6c7b8be468 user: matt tags: v1.80-dbperf
Changes

Modified common.scm from [fc85f532b1] to [fd6e725fd9].

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    (else "FAIL")))

(define (common:logpro-exit-code->test-status exit-code)
  (status-sym->string (common:logpro-exit-code->status-sym exit-code)))

;; 
(defstruct remote





  (hh-dat            (let ((res (or (server:choose-server *toppath* 'homehost)
				    (cons #f #f))))
		       (assert (pair? res)(conc "FATAL: hh-dat should be a pair, got "res))
		       res))
  (server-url        #f) ;; (server:check-if-running *toppath*) #f))
  (server-id         #f)
  (server-info       #f) ;; (if *toppath* (server:check-if-running *toppath*) #f))







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    (else "FAIL")))

(define (common:logpro-exit-code->test-status exit-code)
  (status-sym->string (common:logpro-exit-code->status-sym exit-code)))

;; 
(defstruct remote

  ;; transport to be used
  ;; http              - use http-transport
  ;; http-read-cached  - use http-transport for writes but in-mem cached for reads
  (rmode            'http)
  (hh-dat            (let ((res (or (server:choose-server *toppath* 'homehost)
				    (cons #f #f))))
		       (assert (pair? res)(conc "FATAL: hh-dat should be a pair, got "res))
		       res))
  (server-url        #f) ;; (server:check-if-running *toppath*) #f))
  (server-id         #f)
  (server-info       #f) ;; (if *toppath* (server:check-if-running *toppath*) #f))
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					#t
					#f))
			  (else
			   (debug:print 0 *default-log-port* "ERROR: Bad server force setting " force-setting ", forcing server.")
			   #t)))) ;; default to requiring server
    (if force-result
	(begin
	  (debug:print-info 0 *default-log-port* "forcing use of server, force setting is \"" force-setting "\".")
	  #t)
	#f)))

;;======================================================================
;; M I S C   L I S T S
;;======================================================================








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					#t
					#f))
			  (else
			   (debug:print 0 *default-log-port* "ERROR: Bad server force setting " force-setting ", forcing server.")
			   #t)))) ;; default to requiring server
    (if force-result
	(begin
	  (debug:print-info 0 *default-log-port* "ATTENTION! Forcing use of server, force setting is \"" force-setting "\".")
	  #t)
	#f)))

;;======================================================================
;; M I S C   L I S T S
;;======================================================================

Modified rmt.scm from [22216f2b37] to [a2b373e5f1].

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	  (set! *runremote* (make-remote))
          (let* ((server-info (remote-server-info *runremote*))) 
            (if server-info
		(begin
			(remote-server-url-set! *runremote* (server:record->url server-info))
			(remote-server-id-set! *runremote* (server:record->id server-info)))))  
	  (set! runremote   *runremote*))) ;; new runremote will come from this on next iteration
    



    ;; DOT SET_HOMEHOST; // leaving off - doesn't really add to the clarity
    ;; DOT MUTEXLOCK -> SET_HOMEHOST [label="no homehost?"];
    ;; DOT SET_HOMEHOST -> MUTEXLOCK;
    ;; ensure we have a homehost record
    (if (or (not (pair? (remote-hh-dat runremote)))  ;; not on homehost
	    (not (cdr (remote-hh-dat runremote))))   ;; not on homehost
	(thread-sleep! 0.1) ;; since we shouldn't get here, delay a little
	(let ((hh-data (server:choose-server areapath 'homehost)))
	  (remote-hh-dat-set! runremote (or hh-data (cons #f #f)))))
    
    ;;(print "BB> readonly-mode is "readonly-mode" dbfile is "dbfile)
    (cond
     #;((> (- (current-seconds)(remote-connect-time runremote)) 180) ;; reconnect to server every 180 seconds
      (debug:print 0 *default-log-port* "Forcing reconnect to server(s) due to 180 second timeout.")
      (set! *runremote* #f)
      ;; BUG: close-connections should go here?
      (mutex-unlock! *rmt-mutex*)
      (rmt:send-receive cmd rid params attemptnum: 1 area-dat: area-dat))
     
     ;;DOT EXIT;
     ;;DOT MUTEXLOCK -> EXIT [label="> 15 attempts"]; {rank=same "case 1" "EXIT" }
     ;; give up if more than 150 attempts
     ((> attemptnum 150)
      (debug:print 0 *default-log-port* "ERROR: 150 tries to start/connect to server. Giving up.")
      (exit 1))

     ;;DOT CASE2 [label="local\nreadonly\nquery"];
     ;;DOT MUTEXLOCK -> CASE2; {rank=same "case 2" CASE2}
     ;;DOT CASE2 -> "rmt:open-qry-close-locally";
     ;; readonly mode, read request-  handle it - case 2
     ((and readonly-mode
           (member cmd api:read-only-queries)) 
      (mutex-unlock! *rmt-mutex*)
      (debug:print-info 12 *default-log-port* "rmt:send-receive, case 2")
      (rmt:open-qry-close-locally cmd 0 params)
      )

     ;;DOT CASE3 [label="write in\nread-only mode"];
     ;;DOT MUTEXLOCK -> CASE3 [label="readonly\nmode?"]; {rank=same "case 3" CASE3}
     ;;DOT CASE3 -> "#f";
     ;; readonly mode, write request.  Do nothing, return #f
     (readonly-mode (extras-readonly-mode *rmt-mutex* *default-log-port* cmd params))

     ;; This block was for pre-emptively resetting the connection if there had been no communication for some time.
     ;; I don't think it adds any value. If the server is not there, just fail and start a new connection.
     ;; also, the expire-time calculation might not be correct. We want, time-since-last-server-access > (server:get-timeout)
     ;;
     ;;DOT CASE4 [label="reset\nconnection"];
     ;;DOT MUTEXLOCK -> CASE4 [label="have connection,\nlast_access > expire_time"]; {rank=same "case 4" CASE4}
     ;;DOT CASE4 -> "rmt:send-receive";
     ;; reset the connection if it has been unused too long
     ((and runremote
           (remote-api-url runremote)
	   (> (current-seconds) ;; if it has been more than server-timeout seconds since last contact, close this connection and start a new on
	      (+ (remote-last-access runremote)
		 (remote-server-timeout runremote))))
      (debug:print-info 0 *default-log-port* "Connection to " (remote-server-url runremote) " expired due to no accesses in " (remote-server-timeout runremote) " seconds, forcing new connection.")
      (http-transport:close-connections runremote)
      ;; moving this setting of runremote conndat to #f to inside the http-transport:close-connections
      ;; (remote-conndat-set! runremote #f) ;; invalidate the connection, thus forcing a new connection.
      (mutex-unlock! *rmt-mutex*)
      (rmt:send-receive cmd rid params attemptnum: attemptnum))
     
     ;;DOT CASE5 [label="local\nread"];
     ;;DOT MUTEXLOCK -> CASE5 [label="server not required,\non homehost,\nread-only query"]; {rank=same "case 5" CASE5};
     ;;DOT CASE5 -> "rmt:open-qry-close-locally";

     ;; on homehost and this is a read
     ((and (not (remote-force-server runremote)) ;; honor forced use of server, i.e. server NOT required
	   (rmt:on-homehost? runremote)
           (member cmd api:read-only-queries))   ;; this is a read
      (mutex-unlock! *rmt-mutex*)
      (debug:print-info 12 *default-log-port* "rmt:send-receive, case  5")
      (rmt:open-qry-close-locally cmd 0 params))

     ;;DOT CASE6 [label="init\nremote"];
     ;;DOT MUTEXLOCK -> CASE6 [label="on homehost,\nwrite query,\nhave server,\ncan't reach it"]; {rank=same "case 6" CASE6};
     ;;DOT CASE6 -> "rmt:send-receive";
     ;; on homehost and this is a write, we already have a server, but server has died

     ;; reinstate this keep-alive section but inject a time condition into the (add ...
     ;;
     ;; ((and (cdr (remote-hh-dat runremote))           ;; on homehost
     ;;       (not (member cmd api:read-only-queries))  ;; this is a write
     ;;       (remote-server-url runremote)             ;; have a server
     ;;       (not (server:ping (remote-server-url runremote) (remote-server-id runremote))))  ;; server has died. NOTE: this is not a cheap call! Need better approach.
     ;;  (debug:print 0 *default-log-port* "WARNING: server appears to have died, trying to reconnect, case 6")
     ;;  (http-transport:close-connections area-dat: runremote) ;; make sure to clean up
     ;;  (set! *runremote* (make-remote))
     ;;  (let* ((server-info (remote-server-info *runremote*))) 
     ;;        (if server-info
     ;; 		(begin
     ;; 		  (remote-server-url-set! *runremote* (server:record->url server-info))
     ;;              (remote-server-id-set! *runremote* (server:record->id server-info)))))
     ;;  (remote-force-server-set! runremote (common:force-server?))
     ;;  (mutex-unlock! *rmt-mutex*)
     ;;  (debug:print-info 12 *default-log-port* "rmt:send-receive, case  6")
     ;;  (rmt:send-receive cmd rid params attemptnum: attemptnum))

     ;;DOT CASE7 [label="homehost\nwrite"];
     ;;DOT MUTEXLOCK -> CASE7 [label="server not required,\non homehost,\na write,\nhave a server"]; {rank=same "case 7" CASE7};
     ;;DOT CASE7 -> "rmt:open-qry-close-locally";
     ;; on homehost and this is a write, we already have a server
     ((and (not (remote-force-server runremote))     ;; honor forced use of server, i.e. server NOT required
	   (cdr (remote-hh-dat runremote))           ;; on homehost
           (not (member cmd api:read-only-queries))  ;; this is a write
           (remote-server-url runremote))            ;; have a server (needed to sync written data back)
      (mutex-unlock! *rmt-mutex*)
      (debug:print-info 12 *default-log-port* "rmt:send-receive, case  4.1")
      (rmt:open-qry-close-locally cmd 0 params))

     ;;DOT CASE8 [label="force\nserver"];
     ;;DOT MUTEXLOCK -> CASE8 [label="server not required,\nhave homehost info,\nno connection yet,\nnot a read-only query"]; {rank=same "case 8" CASE8};
     ;;DOT CASE8 -> "rmt:open-qry-close-locally";
     ;;  on homehost, no server contact made and this is a write, passively start a server 
     ((and (not (remote-force-server runremote))     ;; honor forced use of server, i.e. server NOT required
	   (cdr (remote-hh-dat runremote))           ;; have homehost
           (not (remote-server-url runremote))       ;; no connection yet
	   (not (member cmd api:read-only-queries))) ;; not a read-only query
      (debug:print-info 12 *default-log-port* "rmt:send-receive, case  8")
      (let ((server-info  (server:check-if-running *toppath*))) ;; (server:read-dotserver->url *toppath*))) ;; (server:check-if-running *toppath*))) ;; Do NOT want to run server:check-if-running - very expensive to do for every write call
	(if server-info
	    (begin
              (remote-server-url-set! runremote (server:record->url server-info)) ;; the string can be consumed by the client setup if needed
              (remote-server-id-set! runremote (server:record->id server-info)))  
	    (if (common:force-server?)
		(server:start-and-wait *toppath*)
		(server:kind-run *toppath*)))
      (remote-force-server-set! runremote (common:force-server?))
      (mutex-unlock! *rmt-mutex*)
      (debug:print-info 12 *default-log-port* "rmt:send-receive, case  8.1")
      (rmt:open-qry-close-locally cmd 0 params)))

     ;;DOT CASE9 [label="force server\nnot on homehost"];
     ;;DOT MUTEXLOCK -> CASE9 [label="no connection\nand either require server\nor not on homehost"]; {rank=same "case 9" CASE9};
     ;;DOT CASE9 -> "start\nserver" -> "rmt:send-receive";
     ((or (and (remote-force-server runremote)              ;; we are forcing a server and don't yet have a connection to one
	       (not (remote-api-url runremote)))
	  (and (not (cdr (remote-hh-dat runremote)))        ;; not on a homehost 
	       (not (remote-api-url runremote))))           ;; and no connection
      (debug:print-info 12 *default-log-port* "rmt:send-receive, case 9, hh-dat: " (remote-hh-dat runremote) " runremote: " (remote->alist runremote))
      (mutex-unlock! *rmt-mutex*)
      (if (not (server:check-if-running *toppath*)) ;; who knows, maybe one has started up?
	  (server:start-and-wait *toppath*))
      ;; was: (remote-conndat-set! runremote (rmt:get-connection-info *toppath* runremote)) ;; calls client:setup which calls client:setup-http
      (set! runremote (rmt:get-connection-info *toppath* runremote)) ;; calls client:setup which calls client:setup-http
      (rmt:send-receive cmd rid params attemptnum: attemptnum)) ;; TODO: add back-off timeout as

     ;;DOT CASE10 [label="on homehost"];
     ;;DOT MUTEXLOCK -> CASE10 [label="server not required,\non homehost"]; {rank=same "case 10" CASE10};
     ;;DOT CASE10 -> "rmt:open-qry-close-locally";
     ;; all set up if get this far, dispatch the query
     ((and (not (remote-force-server runremote))
	   (cdr (remote-hh-dat runremote))) ;; we are on homehost
      (mutex-unlock! *rmt-mutex*)
      (debug:print-info 12 *default-log-port* "rmt:send-receive, case 10")
      (rmt:open-qry-close-locally cmd (if rid rid 0) params))

     ;;DOT CASE11 [label="send_receive"];
     ;;DOT MUTEXLOCK -> CASE11 [label="else"]; {rank=same "case 11" CASE11};
     ;;DOT CASE11 -> "rmt:send-receive" [label="call failed"];
     ;;DOT CASE11 -> "RESULT" [label="call succeeded"];
     ;; not on homehost, do server query
     (else (extras-case-11 *default-log-port* runremote cmd params attemptnum rid)))))
    ;;DOT }

;; bunch of small functions factored out of send-receive to make debug easier
;;

(define (extras-case-11 *default-log-port* runremote cmd params attemptnum rid)
  ;; (mutex-unlock! *rmt-mutex*)
  (debug:print-info 12 *default-log-port* "rmt:send-receive, case  9")







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	  (set! *runremote* (make-remote))
          (let* ((server-info (remote-server-info *runremote*))) 
            (if server-info
		(begin
			(remote-server-url-set! *runremote* (server:record->url server-info))
			(remote-server-id-set! *runremote* (server:record->id server-info)))))  
	  (set! runremote   *runremote*))) ;; new runremote will come from this on next iteration

    (http-transport-handler runremote cmd rid params attemptnum area-dat areapath readonly-mode)))

(define (http-transport-handler runremote cmd rid params attemptnum area-dat areapath readonly-mode)
  ;; DOT SET_HOMEHOST; // leaving off - doesn't really add to the clarity
  ;; DOT MUTEXLOCK -> SET_HOMEHOST [label="no homehost?"];
  ;; DOT SET_HOMEHOST -> MUTEXLOCK;
  ;; ensure we have a homehost record
  (if (or (not (pair? (remote-hh-dat runremote)))  ;; not on homehost
	  (not (cdr (remote-hh-dat runremote))))   ;; not on homehost
      (thread-sleep! 0.1) ;; since we shouldn't get here, delay a little
      (let ((hh-data (server:choose-server areapath 'homehost)))
	(remote-hh-dat-set! runremote (or hh-data (cons #f #f)))))
  
  ;;(print "BB> readonly-mode is "readonly-mode" dbfile is "dbfile)
  (cond
   #;((> (- (current-seconds)(remote-connect-time runremote)) 180) ;; reconnect to server every 180 seconds
   (debug:print 0 *default-log-port* "Forcing reconnect to server(s) due to 180 second timeout.")
   (set! *runremote* #f)
   ;; BUG: close-connections should go here?
   (mutex-unlock! *rmt-mutex*)
   (rmt:send-receive cmd rid params attemptnum: 1 area-dat: area-dat))
   
   ;;DOT EXIT;
   ;;DOT MUTEXLOCK -> EXIT [label="> 15 attempts"]; {rank=same "case 1" "EXIT" }
   ;; give up if more than 150 attempts
   ((> attemptnum 150)
    (debug:print 0 *default-log-port* "ERROR: 150 tries to start/connect to server. Giving up.")
    (exit 1))

   ;;DOT CASE2 [label="local\nreadonly\nquery"];
   ;;DOT MUTEXLOCK -> CASE2; {rank=same "case 2" CASE2}
   ;;DOT CASE2 -> "rmt:open-qry-close-locally";
   ;; readonly mode, read request-  handle it - case 2
   ((and readonly-mode
         (member cmd api:read-only-queries)) 
    (mutex-unlock! *rmt-mutex*)
    (debug:print-info 12 *default-log-port* "rmt:send-receive, case 2")
    (rmt:open-qry-close-locally cmd 0 params)
    )

   ;;DOT CASE3 [label="write in\nread-only mode"];
   ;;DOT MUTEXLOCK -> CASE3 [label="readonly\nmode?"]; {rank=same "case 3" CASE3}
   ;;DOT CASE3 -> "#f";
   ;; readonly mode, write request.  Do nothing, return #f
   (readonly-mode (extras-readonly-mode *rmt-mutex* *default-log-port* cmd params))

   ;; This block was for pre-emptively resetting the connection if there had been no communication for some time.
   ;; I don't think it adds any value. If the server is not there, just fail and start a new connection.
   ;; also, the expire-time calculation might not be correct. We want, time-since-last-server-access > (server:get-timeout)
   ;;
   ;;DOT CASE4 [label="reset\nconnection"];
   ;;DOT MUTEXLOCK -> CASE4 [label="have connection,\nlast_access > expire_time"]; {rank=same "case 4" CASE4}
   ;;DOT CASE4 -> "rmt:send-receive";
   ;; reset the connection if it has been unused too long
   ((and runremote
         (remote-api-url runremote)
	 (> (current-seconds) ;; if it has been more than server-timeout seconds since last contact, close this connection and start a new on
	    (+ (remote-last-access runremote)
	       (remote-server-timeout runremote))))
    (debug:print-info 0 *default-log-port* "Connection to " (remote-server-url runremote) " expired due to no accesses in " (remote-server-timeout runremote) " seconds, forcing new connection.")
    (http-transport:close-connections runremote)
    ;; moving this setting of runremote conndat to #f to inside the http-transport:close-connections
    ;; (remote-conndat-set! runremote #f) ;; invalidate the connection, thus forcing a new connection.
    (mutex-unlock! *rmt-mutex*)
    (rmt:send-receive cmd rid params attemptnum: attemptnum))
   
   ;;DOT CASE5 [label="local\nread"];
   ;;DOT MUTEXLOCK -> CASE5 [label="server not required,\non homehost,\nread-only query"]; {rank=same "case 5" CASE5};
   ;;DOT CASE5 -> "rmt:open-qry-close-locally";

   ;; on homehost and this is a read
   ((and (not (remote-force-server runremote)) ;; honor forced use of server, i.e. server NOT required
	 (rmt:on-homehost? runremote)
         (member cmd api:read-only-queries))   ;; this is a read
    (mutex-unlock! *rmt-mutex*)
    (debug:print-info 12 *default-log-port* "rmt:send-receive, case  5")
    (rmt:open-qry-close-locally cmd 0 params))

   ;;DOT CASE6 [label="init\nremote"];
   ;;DOT MUTEXLOCK -> CASE6 [label="on homehost,\nwrite query,\nhave server,\ncan't reach it"]; {rank=same "case 6" CASE6};
   ;;DOT CASE6 -> "rmt:send-receive";
   ;; on homehost and this is a write, we already have a server, but server has died

   ;; reinstate this keep-alive section but inject a time condition into the (add ...
   ;;
   ;; ((and (cdr (remote-hh-dat runremote))           ;; on homehost
   ;;       (not (member cmd api:read-only-queries))  ;; this is a write
   ;;       (remote-server-url runremote)             ;; have a server
   ;;       (not (server:ping (remote-server-url runremote) (remote-server-id runremote))))  ;; server has died. NOTE: this is not a cheap call! Need better approach.
   ;;  (debug:print 0 *default-log-port* "WARNING: server appears to have died, trying to reconnect, case 6")
   ;;  (http-transport:close-connections area-dat: runremote) ;; make sure to clean up
   ;;  (set! *runremote* (make-remote))
   ;;  (let* ((server-info (remote-server-info *runremote*))) 
   ;;        (if server-info
   ;; 		(begin
   ;; 		  (remote-server-url-set! *runremote* (server:record->url server-info))
   ;;              (remote-server-id-set! *runremote* (server:record->id server-info)))))
   ;;  (remote-force-server-set! runremote (common:force-server?))
   ;;  (mutex-unlock! *rmt-mutex*)
   ;;  (debug:print-info 12 *default-log-port* "rmt:send-receive, case  6")
   ;;  (rmt:send-receive cmd rid params attemptnum: attemptnum))

   ;;DOT CASE7 [label="homehost\nwrite"];
   ;;DOT MUTEXLOCK -> CASE7 [label="server not required,\non homehost,\na write,\nhave a server"]; {rank=same "case 7" CASE7};
   ;;DOT CASE7 -> "rmt:open-qry-close-locally";
   ;; on homehost and this is a write, we already have a server
   ((and (not (remote-force-server runremote))     ;; honor forced use of server, i.e. server NOT required
	 (cdr (remote-hh-dat runremote))           ;; on homehost
         (not (member cmd api:read-only-queries))  ;; this is a write
         (remote-server-url runremote))            ;; have a server (needed to sync written data back)
    (mutex-unlock! *rmt-mutex*)
    (debug:print-info 12 *default-log-port* "rmt:send-receive, case  4.1")
    (rmt:open-qry-close-locally cmd 0 params))

   ;;DOT CASE8 [label="force\nserver"];
   ;;DOT MUTEXLOCK -> CASE8 [label="server not required,\nhave homehost info,\nno connection yet,\nnot a read-only query"]; {rank=same "case 8" CASE8};
   ;;DOT CASE8 -> "rmt:open-qry-close-locally";
   ;;  on homehost, no server contact made and this is a write, passively start a server 
   ((and (not (remote-force-server runremote))     ;; honor forced use of server, i.e. server NOT required
	 (cdr (remote-hh-dat runremote))           ;; have homehost
         (not (remote-server-url runremote))       ;; no connection yet
	 (not (member cmd api:read-only-queries))) ;; not a read-only query
    (debug:print-info 12 *default-log-port* "rmt:send-receive, case  8")
    (let ((server-info  (server:check-if-running *toppath*))) ;; (server:read-dotserver->url *toppath*))) ;; (server:check-if-running *toppath*))) ;; Do NOT want to run server:check-if-running - very expensive to do for every write call
      (if server-info
	  (begin
            (remote-server-url-set! runremote (server:record->url server-info)) ;; the string can be consumed by the client setup if needed
            (remote-server-id-set! runremote (server:record->id server-info)))  
	  (if (common:force-server?)
	      (server:start-and-wait *toppath*)
	      (server:kind-run *toppath*)))
      (remote-force-server-set! runremote (common:force-server?))
      (mutex-unlock! *rmt-mutex*)
      (debug:print-info 12 *default-log-port* "rmt:send-receive, case  8.1")
      (rmt:open-qry-close-locally cmd 0 params)))

   ;;DOT CASE9 [label="force server\nnot on homehost"];
   ;;DOT MUTEXLOCK -> CASE9 [label="no connection\nand either require server\nor not on homehost"]; {rank=same "case 9" CASE9};
   ;;DOT CASE9 -> "start\nserver" -> "rmt:send-receive";
   ((or (and (remote-force-server runremote)              ;; we are forcing a server and don't yet have a connection to one
	     (not (remote-api-url runremote)))
	(and (not (cdr (remote-hh-dat runremote)))        ;; not on a homehost 
	     (not (remote-api-url runremote))))           ;; and no connection
    (debug:print-info 12 *default-log-port* "rmt:send-receive, case 9, hh-dat: " (remote-hh-dat runremote) " runremote: " (remote->alist runremote))
    (mutex-unlock! *rmt-mutex*)
    (if (not (server:check-if-running *toppath*)) ;; who knows, maybe one has started up?
	(server:start-and-wait *toppath*))
    ;; was: (remote-conndat-set! runremote (rmt:get-connection-info *toppath* runremote)) ;; calls client:setup which calls client:setup-http
    (set! runremote (rmt:get-connection-info *toppath* runremote)) ;; calls client:setup which calls client:setup-http
    (rmt:send-receive cmd rid params attemptnum: attemptnum)) ;; TODO: add back-off timeout as

   ;;DOT CASE10 [label="on homehost"];
   ;;DOT MUTEXLOCK -> CASE10 [label="server not required,\non homehost"]; {rank=same "case 10" CASE10};
   ;;DOT CASE10 -> "rmt:open-qry-close-locally";
   ;; all set up if get this far, dispatch the query
   ((and (not (remote-force-server runremote))
	 (cdr (remote-hh-dat runremote))) ;; we are on homehost
    (mutex-unlock! *rmt-mutex*)
    (debug:print-info 12 *default-log-port* "rmt:send-receive, case 10")
    (rmt:open-qry-close-locally cmd (if rid rid 0) params))

   ;;DOT CASE11 [label="send_receive"];
   ;;DOT MUTEXLOCK -> CASE11 [label="else"]; {rank=same "case 11" CASE11};
   ;;DOT CASE11 -> "rmt:send-receive" [label="call failed"];
   ;;DOT CASE11 -> "RESULT" [label="call succeeded"];
   ;; not on homehost, do server query
   (else (extras-case-11 *default-log-port* runremote cmd params attemptnum rid))))
;;DOT }

;; bunch of small functions factored out of send-receive to make debug easier
;;

(define (extras-case-11 *default-log-port* runremote cmd params attemptnum rid)
  ;; (mutex-unlock! *rmt-mutex*)
  (debug:print-info 12 *default-log-port* "rmt:send-receive, case  9")