add function to clear out the clickhouse failure queue

trackernet.lisp

@@ -4086,3 +4086,18 @@ Return four values: a set of nodes, edges, weights, and a new->old edge mapping.
     for ltid in (get-all "lt:*")
     when (eql (red:ttl ltid) -1)
       collect ltid))
+
+(defun clear-clickhouse-queue ()
+  "Clear the queue of clickhouse failures."
+  ;; make sure we have a connection first
+  (assert (string= "PONG" (red:ping)))
+  (loop
+    for train = (red:spop "clickhouse-failures")
+    while train
+    do (handler-bind
+           ((serious-condition
+              (lambda (c)
+                (declare (ignore c))
+                (log:warn "reinserting train into failures due to condition")
+                (red:sadd "clickhouse-failures" train))))
+         (clickhouse-insert-live (cpk-unbase64 train)))))