How to solve the huge HTTPRL error that fills down all of Cron \ Status report?
The solution (or at least work around?) could be what is described in Comment # 8 of Issue # 2450725 related to the HTTP Parallel Request &amp; Threading Library module:

change &quot;'timeout' =&gt; 7,&quot; to &quot;'timeout' =&gt; 1,&quot;
This timeout is used in lock_acquire() that probably locks Drupal for 7 seconds, but in httprl config httprp waits only 5 seconds for a response.

Comment # 17 in that issue also contains a corresponding patch, which looks like so:
diff --git a/httprl.install b/httprl.install
index d7e2963..e2d4f04 100644
--- a/httprl.install
+++ b/httprl.install
@@ -177,7 +177,7 @@ function httprl_install_http_test($mode, $blocking = FALSE) {
       // Setup options array.
       'options' =&gt; array(
         'blocking' =&gt; $blocking,
-        'timeout' =&gt; 7,
+        'timeout' =&gt; 1,
         'max_redirects' =&gt; 0,
         'headers' =&gt; $headers,
       ),