[mod] [#462] Don't throw by default on Ajax read timeouts

It's generally not actionable when this happens, so the objective
here is just to provide info.

The logging can be disabled either through normal log filtering
(e.g. by ns for Timbre/Telemere, or id for Telemere), or by
adjusting the on-timeout handler.

Author: ptaoussanis

src/taoensso/sente/server_adapters/community/jetty.clj

@@ -69,15 +69,15 @@
       true))
 
   ISenteJettyAjaxChannel
-  (ajax-read! [_sch]
-    (let [{:keys [ajax-resp-timeout-ms]} adapter-opts
+  (ajax-read! [sch]
+    (let [{:keys [ajax-resp-timeout-ms on-ajax-resp-timeout]} adapter-opts
           resp
           (if ajax-resp-timeout-ms
             (deref resp-promise_ ajax-resp-timeout-ms ::timeout)
             (deref resp-promise_))]
 
       (if (= resp ::timeout)
-        (throw (ex-info "Ajax read timeout" {:timeout-msecs ajax-resp-timeout-ms}))
+        (when-let [f on-ajax-resp-timeout] (f sch ring-req))
         resp))))
 
 (defn- ajax-ch
@@ -115,15 +115,22 @@
   Supports Jetty 11, 12.
 
   Options:
-     `:ajax-resp-timeout-ms` - Max msecs to wait for Ajax responses (default 60 secs),
-                               exception thrown on timeout.
+       `:ajax-resp-timeout-ms` - Max msecs to wait for Ajax responses (default 60 secs)
+    `:on-ajax-resp-timeout`    - (fn [ServerChan ring-req]) to trigger after above timeout (logs by default)
 
   [1] Ref. <https://github.com/ring-clojure/ring/tree/master/ring-jetty-adapter>."
   ([] (get-sch-adapter nil))
   ([{:as   opts
-     :keys [ajax-resp-timeout-ms]
-     :or   {ajax-resp-timeout-ms (* 60 1000)}}]
+     :keys [ajax-resp-timeout-ms on-ajax-resp-timeout]
+     :or
+     {   ajax-resp-timeout-ms (* 60 1000)
+      on-ajax-resp-timeout
+      (fn [sch ring-req]
+        (trove/log!
+          {:level :warn, :id :sente.server.jetty/ajax-read-timeout,
+           :data ring-req}))}}]
 
    (JettyServerChanAdapter.
      (assoc opts
-       :ajax-resp-timeout-ms ajax-resp-timeout-ms))))
+          :ajax-resp-timeout-ms ajax-resp-timeout-ms
+       :on-ajax-resp-timeout on-ajax-resp-timeout))))

src/taoensso/sente/server_adapters/community/undertow.clj

@@ -3,7 +3,8 @@
   (:require
     [ring.adapter.undertow.websocket :as websocket]
     [ring.adapter.undertow.response  :as response]
-    [taoensso.sente.interfaces :as i])
+    [taoensso.sente.interfaces :as i]
+    [taoensso.trove :as trove])
   (:import
     [io.undertow.websockets.core WebSocketChannel]
     [io.undertow.server HttpServerExchange]
@@ -52,14 +53,14 @@
 
   ISenteUndertowAjaxChannel
   (ajax-read! [sch]
-    (let [{:keys [ajax-resp-timeout-ms]} adapter-opts
+    (let [{:keys [ajax-resp-timeout-ms on-ajax-resp-timeout]} adapter-opts
           resp
           (if ajax-resp-timeout-ms
             (deref resp-promise_ ajax-resp-timeout-ms ::timeout)
             (deref resp-promise_))]
 
       (if (= resp ::timeout)
-        (throw (ex-info "Ajax read timeout" {:timeout-msecs ajax-resp-timeout-ms}))
+        (when-let [f on-ajax-resp-timeout] (f sch ring-req))
         resp))))
 
 (defn- ajax-ch
@@ -91,15 +92,22 @@
   "Returns a Sente `ServerChan` adapter for `ring-undertow-adapter` [1].
 
   Options:
-     `:ajax-resp-timeout-ms` - Max msecs to wait for Ajax responses (default 60 secs),
-                               exception thrown on timeout.
+        `:ajax-resp-timeout-ms` - Max msecs to wait for Ajax responses (default 60 secs)
+     `:on-ajax-resp-timeout`    - (fn [ServerChan ring-req]) to trigger after above timeout (logs by default)
 
   [1] Ref. <https://github.com/luminus-framework/ring-undertow-adapter>."
   ([] (get-sch-adapter nil))
   ([{:as   opts
-     :keys [ajax-resp-timeout-ms]
-     :or   {ajax-resp-timeout-ms (* 60 1000)}}]
+     :keys [ajax-resp-timeout-ms on-ajax-resp-timeout]
+     :or
+     {   ajax-resp-timeout-ms (* 60 1000)
+      on-ajax-resp-timeout
+      (fn [sch ring-req]
+        (trove/log!
+          {:level :warn, :id :sente.server.undertow/ajax-read-timeout,
+           :data ring-req}))}}]
 
    (UndertowServerChanAdapter.
      (assoc opts
-       :ajax-resp-timeout-ms ajax-resp-timeout-ms))))
+          :ajax-resp-timeout-ms ajax-resp-timeout-ms
+       :on-ajax-resp-timeout on-ajax-resp-timeout))))