Megatest

	(begin
	  (debug:print-error 0 *default-log-port* "" fnamejnl " found, moving it to old dir as " tmpjnl)
	  (system (conc "cd " dbdir ";mkdir -p old;cat " fnamejnl " > old/" tmpjnl))
	  (system (conc "rm -f " dbdir "/" fnamejnl))))
    ;; attempt to recreate database
    (system (conc "cd " dbdir ";sqlite3 old/" tmpname " .dump | sqlite3 " fname))))
    
;; return #f to indicate the dbdat should be closed/reopened
;; else return dbdat
;;
(define (db:repair-db dbdat #!key (numtries 1))
  (let* ((dbpath   (db:dbdat-get-path        dbdat))
	 (dbdir    (pathname-directory       dbpath))
	 (fname    (pathname-strip-directory dbpath)))
    (debug:print-info 0 *default-log-port* "Checking db " dbpath " for errors.")
    (cond
     ((not (file-write-access? dbdir))
      (debug:print 0 *default-log-port* "WARNING: can't write to " dbdir ", can't fix " fname)
      #f)

     ;; handle special cases, megatest.db and monitor.db
     ;; 
     ;;  NOPE: apply this same approach to all db files
     ;;
     (else ;; ((equal? fname "megatest.db") ;; this file can be regenerated if needed
      (handle-exceptions
       exn
       (begin
	 ;; (db:move-and-recreate-db dbdat)
	 (if (> numtries 0)
	     (db:repair-db dbdat numtries: (- numtries 1))
	     #f)
	 (debug:print 0 *default-log-port* "FATAL: file " dbpath " was found corrupted, an attempt to fix has been made but you must start over.")
	 (debug:print 0 *default-log-port*
		      "   check the following:\n"
		      "      1. full directories, look in ~/ /tmp and " dbdir "\n"
		      "      2. write access to " dbdir "\n\n"
		      "   if the automatic recovery failed you may be able to recover data by doing \"" 
		      (if (member fname '("megatest.db" "monitor.db"))
			  "megatest -cleanup-db"
			  "megatest -import-megatest.db;megatest -cleanup-db")
		      "\"\n")
	 (exit) ;; we can not safely continue when a db was corrupted - even if fixed.
	 )
       ;; test read/write access to the database
       (let ((db (sqlite3:open-database dbpath)))
	 (cond
	  ((equal? fname "megatest.db")
	   (sqlite3:execute db "DELETE FROM tests WHERE state='DELETED';"))
	  ((equal? fname "main.db")
	   (sqlite3:execute db "DELETE FROM runs WHERE state='deleted';"))
	  ((string-match "\\d.db" fname)
	   (sqlite3:execute db "UPDATE tests SET state='DELETED' WHERE state='DELETED';"))
	  ((equal? fname "monitor.db")
	   (sqlite3:execute "DELETE FROM servers WHERE state LIKE 'defunct%';"))
	  (else
	   (sqlite3:execute db "vacuum;")))
	 
	 (finalize! db)
	 #t))))))
    
;; tbls is ( ("tablename" ( "field1" [#f|proc1] ) ( "field2" [#f|proc2] ) .... ) )
;; db's are dbdat's
;;
;; if last-update specified ("field-name" . time-in-seconds)
;;    then sync only records where field-name >= time-in-seconds
;;    IFF field-name exists
;;
(define (db:sync-tables tbls last-update fromdb todb . slave-dbs)
  (handle-exceptions
   exn
   (begin
     (debug:print 0 *default-log-port* "EXCEPTION: database probably overloaded or unreadable in db:sync-tables.")
     (print-call-chain (current-error-port))
     (debug:print 0 *default-log-port* " message: " ((condition-property-accessor 'exn 'message) exn))
     (debug:print 5 *default-log-port* "exn=" (condition->list exn))
     (debug:print 0 *default-log-port* " status:  " ((condition-property-accessor 'sqlite3 'status) exn))
     (debug:print 0 *default-log-port* " src db:  " (db:dbdat-get-path fromdb))
     (for-each (lambda (dbdat)
		 (let ((dbpath (db:dbdat-get-path dbdat)))
		   (debug:print 0 *default-log-port* " dbpath:  " dbpath)
		   (if (not (db:repair-db dbdat))
		       (begin
			 (debug:print-error 0 *default-log-port* "Failed to rebuild " dbpath ", exiting now.")
			 (exit)))))
	       (cons todb slave-dbs))
     
     0)
   ;; this is the work to be done
   (cond
    ((not fromdb) (debug:print 3 *default-log-port* "WARNING: db:sync-tables called with fromdb missing")
     -1)
    ((not todb)   (debug:print 3 *default-log-port* "WARNING: db:sync-tables called with todb missing")
     -2)
    ((not (sqlite3:database? (db:dbdat-get-db fromdb)))
     (debug:print-error 0 *default-log-port* "db:sync-tables called with fromdb not a database " fromdb)
     -3)
    ((not (sqlite3:database? (db:dbdat-get-db todb)))
     (debug:print-error 0 *default-log-port* "db:sync-tables called with todb not a database " todb)
     -4)

    ((not (file-write-access? (db:dbdat-get-path todb)))
     (debug:print-error 0 *default-log-port* "db:sync-tables called with todb not a read-only database " todb)
     -5)
    ((not (null? (let ((readonly-slave-dbs
                        (filter
                         (lambda (dbdat)
                           (not (file-write-access? (db:dbdat-get-path todb))))
                         slave-dbs)))
                   (for-each
                    (lambda (bad-dbdat)
                      (debug:print-error
                       0 *default-log-port* "db:sync-tables called with todb not a read-only database " bad-dbdat))
                    readonly-slave-dbs)
                   readonly-slave-dbs))) -6)
    (else
     (let ((stmts       (make-hash-table)) ;; table-field => stmt
	   (all-stmts   '())              ;; ( ( stmt1 value1 ) ( stml2 value2 ))
	   (numrecs     (make-hash-table))
	   (start-time  (current-milliseconds))
	   (tot-count   0))
       (for-each ;; table
	(lambda (tabledat)
	  (let* ((tablename        (car tabledat))
		 (fields           (cdr tabledat))
		 (has-last-update  (member "last_update" fields))
		 (use-last-update  (cond
				    ((and has-last-update
					  (member "last_update" fields))
				     #t) ;; if given a number, just use it for all fields
				    ((number? last-update) #f) ;; if not matched first entry then ignore last-update for this table
				    ((and (pair? last-update)
					  (member (car last-update)    ;; last-update field name
						  (map car fields))) #t)
				    (last-update
				     (debug:print 0 *default-log-port* "ERROR: parameter last-update for db:sync-tables must be a pair or a number, received: " last-update) ;; found in fields
				     #f)
				    (else
				     #f)))
		 (last-update-value (if use-last-update ;; no need to check for has-last-update - it is already accounted for
					(if (number? last-update)
					    last-update
					    (cdr last-update))
					#f))
		 (last-update-field (if use-last-update
					(if (number? last-update)
					    "last_update"
					    (car last-update))
					#f))
		 (num-fields (length fields))
		 (field->num (make-hash-table))
		 (num->field (apply vector (map car fields))) ;; BBHERE
		 (full-sel   (conc "SELECT " (string-intersperse (map car fields) ",") 
				   " FROM " tablename (if use-last-update ;; apply last-update criteria
							  (conc " WHERE " last-update-field " >= " last-update-value)
							  "")
				   ";"))
		 (full-ins   (conc "INSERT OR REPLACE INTO " tablename " ( " (string-intersperse (map car fields) ",") " ) "
				   " VALUES ( " (string-intersperse (make-list num-fields "?") ",") " );"))
		 (fromdat    '())
		 (fromdats   '())
		 (totrecords 0)
		 (batch-len  (string->number (or (configf:lookup *configdat* "sync" "batchsize") "100")))
		 (todat      (make-hash-table))
		 (count      0)

                 (delay-handicap  (string->number (or (configf:lookup *configdat* "sync" "delay-handicap") "0")))
                 )

	    ;; set up the field->num table
	    (for-each
	     (lambda (field)
	       (hash-table-set! field->num field count)
	       (set! count (+ count 1)))
	     fields)

	    ;; read the source table
	    (sqlite3:for-each-row
	     (lambda (a . b)
	       (set! fromdat (cons (apply vector a b) fromdat))
	       (if (> (length fromdat) batch-len)
		   (begin
		     (set! fromdats (cons fromdat fromdats))
		     (set! fromdat  '())
		     (set! totrecords (+ totrecords 1)))))
	     (db:dbdat-get-db fromdb)
	     full-sel)
	    
	    ;; tack on remaining records in fromdat
	    (if (not (null? fromdat))
		(set! fromdats (cons fromdat fromdats)))

	    (if (common:low-noise-print 120 "sync-records")
		(debug:print-info 4 *default-log-port* "found " totrecords " records to sync"))

	    ;; read the target table; BBHERE
	    (sqlite3:for-each-row
	     (lambda (a . b)
	       (hash-table-set! todat a (apply vector a b)))
	     (db:dbdat-get-db todb)
	     full-sel)

            (when (and delay-handicap (> delay-handicap 0))
              (debug:print-info 0 *default-log-port* "imposing synthetic sync delay of "delay-handicap" seconds since sync/delay-handicap is configured")
              (thread-sleep! delay-handicap)
              (debug:print-info 0 *default-log-port* "synthetic sync delay of "delay-handicap" seconds completed")
              )
            
	    ;; first pass implementation, just insert all changed rows
	    (for-each 
	     (lambda (targdb)
	       (let* ((db     (db:dbdat-get-db targdb))
		      (stmth  (sqlite3:prepare db full-ins)))
		 (db:delay-if-busy targdb) ;; NO WAITING
		 (for-each
		  (lambda (fromdat-lst)
		    (sqlite3:with-transaction
		     db
		     (lambda ()
		       (for-each ;; 
			(lambda (fromrow)
			  (let* ((a    (vector-ref fromrow 0))
				 (curr (hash-table-ref/default todat a #f))
				 (same #t))
			    (let loop ((i 0))
			      (if (or (not curr)
				      (not (equal? (vector-ref fromrow i)(vector-ref curr i))))
				  (set! same #f))
			      (if (and same
				       (< i (- num-fields 1)))
				  (loop (+ i 1))))
			    (if (not same)
				(begin
				  (apply sqlite3:execute stmth (vector->list fromrow))
				  (hash-table-set! numrecs tablename (+ 1 (hash-table-ref/default numrecs tablename 0)))))))
			fromdat-lst))
		  ))
		  fromdats)
		 (sqlite3:finalize! stmth)))
	     (append (list todb) slave-dbs))))
	tbls)
       (let* ((runtime      (- (current-milliseconds) start-time))
	      (should-print (or (debug:debug-mode 12)
				(common:low-noise-print 120 "db sync" (> runtime 500))))) ;; low and high sync times treated as separate.
	 (if should-print (debug:print 3 *default-log-port* "INFO: db sync, total run time " runtime " ms"))
	 (for-each 
	  (lambda (dat)
	    (let ((tblname (car dat))
		  (count   (cdr dat)))
	      (set! tot-count (+ tot-count count))
	      (if (> count 0)
		  (if should-print (debug:print 0 *default-log-port* (format #f "    ~10a ~5a" tblname count))))))
	  (sort (hash-table->alist numrecs)(lambda (a b)(> (cdr a)(cdr b))))))
       tot-count)))))

(define (db:patch-schema-rundb frundb)
  ;;
  ;; remove this some time after September 2016 (added in version v1.6031
  ;;
  (for-each
   (lambda (table-name)
     (handle-exceptions