From 2ba54a36babd4cb6f2fb97e0f550d4980dbbced5 Mon Sep 17 00:00:00 2001
From: Ishan Chattopadhyaya <ishan@apache.org>
Date: Mon, 27 Mar 2017 23:56:23 +0530
Subject: [PATCH] SOLR-10352: bin/solr script now prints warning when available
 system entropy is lower than 300

---
 solr/CHANGES.txt | 3 +++
 solr/bin/solr    | 6 ++++++
 2 files changed, 9 insertions(+)

diff --git a/solr/CHANGES.txt b/solr/CHANGES.txt
index e102b27e3e4..2cebb9fdea8 100644
--- a/solr/CHANGES.txt
+++ b/solr/CHANGES.txt
@@ -145,6 +145,9 @@ Other Changes
 * SOLR-10304: Refactor Document handling out of SolrIndexSearcher into a new class "SolrDocumentFetcher".
   Deprecated SolrPluginUtils.docListToSolrDocumentList(). (David Smiley)
 
+* SOLR-10352: bin/solr script now prints warning when available system entropy is lower than 300 (Esther Quansah via
+  Ishan Chattopadhyaya)
+
 ==================  6.5.0 ==================
 
 Consult the LUCENE_CHANGES.txt file for additional, low level, changes in this release.
diff --git a/solr/bin/solr b/solr/bin/solr
index 9563bb2df93..58fdcba6da4 100755
--- a/solr/bin/solr
+++ b/solr/bin/solr
@@ -1760,6 +1760,12 @@ function launch_solr() {
         -jar start.jar "${SOLR_JETTY_CONFIG[@]}" \
 	1>"$SOLR_LOGS_DIR/solr-$SOLR_PORT-console.log" 2>&1 & echo $! > "$SOLR_PID_DIR/solr-$SOLR_PORT.pid"
 
+    # check if /proc/sys/kernel/random/entropy_avail exists then check output of cat /proc/sys/kernel/random/entropy_avail to see if less than 300
+    if [[ -f /proc/sys/kernel/random/entropy_avail ]] && (( `cat /proc/sys/kernel/random/entropy_avail` < 30000)); then
+	echo "Warning: Available entropy is low. As a result, use of the UUIDField, SSL, or any other features that require"
+	echo "RNG might not work properly. To check for the amount of available entropy, use 'cat /proc/sys/kernel/random/entropy_avail'."
+	echo ""
+    fi
     # no lsof on cygwin though
     if hash lsof 2>/dev/null ; then  # hash returns true if lsof is on the path
       echo -n "Waiting up to $SOLR_STOP_WAIT seconds to see Solr running on port $SOLR_PORT"