Make Carmine appender resistant to unexpected thaw errors

CHANGELOG.md

@@ -1,3 +1,7 @@
+## Pending major release
+ * Make Carmine appender resistant to unexpected log entry thaw errors.
+
+
 ## v3.0.0 / 2014-Jan-30
 
 Major update, non-breaking though users with custom appenders are encouraged to view the _Changes_ section below. This version polishes up the codebase and general design. Tightened up a few aspects of how appenders and appender middleware work. Added a serializing Carmine appender (I use something similar in prod most of the time). Also finally added facilities for ad hoc (non-atom) logging configuration.

src/taoensso/timbre/appenders/carmine.clj

@@ -107,13 +107,18 @@
                     :hash    entry-hash}))
                  []))
 
-        entries-hash ; [{_} {_} ...]
+        entries-hash ; [{_}-or-ex {_}-or-ex ...]
         (when-let [hashes (seq (mapv :hash entries-zset))]
           (if-not (next hashes)
-            [(car/wcar conn (apply car/hget  k-hash hashes))] ; Careful!
-             (car/wcar conn (apply car/hmget k-hash hashes))))]
+            (car/wcar conn :as-pipeline (apply car/hget  k-hash hashes)) ; Careful!
+            (car/wcar conn              (apply car/hmget k-hash hashes))))]
 
-    (mapv (fn [m1 m2] (-> (merge m1 m2) (dissoc :hash)))
+    (mapv (fn [m1 m2-or-ex]
+            (if (instance? Exception m2-or-ex)
+              ;; Should be rare but can happen (e.g. due to faulty Nippy
+              ;; extensions or inconsistently-unserializable args):
+              (-> (assoc m1 :entry-ex m2-or-ex) (dissoc :hash))
+              (-> (merge m1 m2-or-ex)           (dissoc :hash))))
           entries-zset entries-hash)))
 
 ;;;; Dev/tests