use max age instead of live data length limit

trackernet.lisp

@@ -24,6 +24,7 @@
 (defparameter *rude-requests-per-minute* 300)
 (defparameter *rescue-ptr-expiry-secs* (* 60 60 3))
 (defparameter *train-live-data-limit* 40000)
+(defparameter *max-train-age-secs* (* 60 60 24))
 (defparameter *rescue-max-dist* 10.0)
 (defparameter *rescue-timediff-threshold* -15)
 (defparameter *max-trackernet-data-age-secs* 300)
@@ -900,13 +901,13 @@
           (length (get-trains pred)))))))
 
 (defun get-archivable-trains ()
-  "Returns a list of all trains that were last updated more than *TRAIN-ACTIVE-EXPIRY-SECS* ago, or have too many records."
+  "Returns a list of all trains that were last updated more than *TRAIN-ACTIVE-EXPIRY-SECS* ago, or were created more than *MAX-TRAIN-AGE-SECS* ago."
   (let* ((trains (get-all "?-train-*"))
+         (age-cutoff (- (get-universal-time) *max-train-age-secs*))
          (cutoff (- (get-universal-time) *train-active-expiry-secs*)))
     (delete-if-not (lambda (train)
                      (or
-;;                      (> (redis-sorted-set-length train)
-;;                         *train-live-data-limit*)
+                      (< (redis-first-score train) age-cutoff)
                       (< (redis-last-score train) cutoff)))
                    trains)))