Major rework, PPSS is now fully asynchronous. There are no while loops polling stuff at an interval.

ppss.sh

@@ -38,7 +38,7 @@ trap 'kill_process; ' INT
 
 # Setting some vars. Do not change. 
 SCRIPT_NAME="Distributed Parallel Processing Shell Script"
-SCRIPT_VERSION="2.22"
+SCRIPT_VERSION="2.30"
 
 # The first argument to this script is always the 'mode'.
 MODE="$1"
@@ -77,6 +77,7 @@ IFS_BACKUP="$IFS"
 INTERVAL="30"                           # Polling interval to check if there are running jobs.
 CPUINFO=/proc/cpuinfo
 PROCESSORS=""
+STOP_KEY=$RANDOM$RANDOM$RANDOM
 
 MIN_JOBS=3
 SSH_SERVER=""                           # Remote server or 'master'.
@@ -94,8 +95,8 @@ SSH_MASTER_PID=""
 
 PPSS_HOME_DIR="ppss"
 ITEM_LOCK_DIR="$PPSS_DIR/PPSS_ITEM_LOCK_DIR"      # Remote directory on master used for item locking.
-PPSS_LOCAL_TMPDIR="$PPSS_DIR/PPSS_TMPDIR"   # Local directory on slave for local processing.
+PPSS_LOCAL_TMPDIR="$PPSS_DIR/PPSS_LOCAL_TMPDIR"   # Local directory on slave for local processing.
-PPSS_LOCAL_OUTPUT="$PPSS_DIR/PPSS_OUTPUT"   # Local directory on slave for local output.
+PPSS_LOCAL_OUTPUT="$PPSS_DIR/PPSS_LOCAL_OUTPUT"   # Local directory on slave for local output.
 TRANSFER_TO_SLAVE="0"                   # Transfer item to slave via (s)cp.
 SECURE_COPY="1"                         # If set, use SCP, Otherwise, use cp.
 REMOTE_OUTPUT_DIR=""                    # Remote directory to which output must be uploaded.
@@ -209,33 +210,17 @@ showusage () {
 
 kill_process () {
 
-    kill $LISTENER_PID >> /dev/null 2>&1
-    while true
-    do
-        JOBS=`ps aux | grep $USER | grep -v grep | grep -v -i screen | grep ppss.sh | grep -i bash | wc -l`
-        if [ "$JOBS" -gt "2" ]
-        then
-            for x in `ps aux | grep $USER | grep -v grep | grep -v -i screen | grep ppss.sh | grep -i bash | awk '{ print $1 }'`
-            do
-                if [ ! "$x" == "$PID" ] && [ ! "$x" == "$$" ]
-                then
-                    kill -9 $x >> /dev/null 2>&1
-                fi
-            done
-            sleep 5
-        else
-            cleanup 
-            echo -en "\033[1B"
-            # The master SSH connection should be killed.
-            if [ ! -z "$SSH_MASTER_PID" ]
-            then
-                kill -9 "$SSH_MASTER_PID"
-            fi
-            echo ""
-            exit 0
-        fi
-    done
 
+    kill $LISTENER_PID > /dev/null 2&>1
+    sleep 1
+    cleanup
+    sleep 1
+    if [ ! -z "$SSH_MASTER_PID" ]
+    then
+        kill -9 "$SSH_MASTER_PID"
+    fi
+    sleep 1
+    log INFO "Finished."
 }
 
 exec_cmd () { 
@@ -752,9 +737,15 @@ erase_ppss () {
     then
         for NODE in `cat $NODES_FILE`
         do
+            does_file_exist "ppss"
+            if [ "$?" == "0" ]
+            then
                 log INFO "Erasing PPSS homedir $PPSS_HOME_DIR from node $NODE."
                 ssh -q $SSH_KEY $SSH_OPTS $USER@$NODE "./$PPSS_HOME_DIR/$0 kill"
                 ssh -q $SSH_KEY $SSH_OPTS $USER@$NODE "rm -rf $PPSS_HOME_DIR"
+            else
+                log INFO "PPSS was not present on node $NODE."
+            fi
         done
     else
         log INFO "Aborting.."
@@ -1294,7 +1285,13 @@ start_single_worker () {
     ERROR=$?
     if [ ! "$ERROR" == "0" ]
     then
-        log DEBUG "Item empty, we are probably almost finished."
+        # If no more items are available, the listener should be
+        # informed that a worker just finished / died.
+        # Tis allows the listener to determine if all processes
+        # are finished and it is time to stop.
+        echo
+        log INFO "Waiting for remaining jobs to finish..."
+        echo "$STOP_KEY" > $FIFO
         return 1
     else
         get_global_lock
@@ -1434,13 +1431,30 @@ commando () {
 
 # This is the listener service. It listens on the pipe for events.
 # A job is executed for every event received.
+# This listener enables fully asynchronous processing.
 listen_for_job () {
 
+    DIED=0
     log DEBUG "Listener started."
     while read event <& 42
     do
-        commando "$event" &
+        # The start_single_worker method sends a special signal to 
+        # inform the listener that a worker is finished.
+        # If all workers are finished, it is time to stop.
+        if [ "$event" == "$STOP_KEY"  ]
+        then
+            ((DIED++))
+            if [ "$DIED" -ge "$MAX_NO_OF_RUNNING_JOBS" ] 
+            then
+                break
+            fi
+            log DEBUG "$((MAX_NO_OF_RUNNING_JOBS-DIED)) jobs are remaining."
+        else
+             commando "$event" &
+        fi
     done
+    kill_process
+    log DEBUG "Listener stopped."
 }
 
 # This starts an number of parallel workers based on the # of parallel jobs allowed.
@@ -1540,7 +1554,7 @@ main () {
                     init_vars
                     test_server
                     get_all_items
-                    listen_for_job "$MAX_NO_OF_RUNNING_JOBS" &
+                    listen_for_job "$MAX_NO_OF_RUNNING_JOBS" & 2>&1 >> /dev/null
                     LISTENER_PID=$!
                     start_all_workers
                     ;;
@@ -1597,7 +1611,7 @@ main () {
                         exec_cmd "rm -f $PAUSE_SIGNAL"
                     fi
                     cleanup
-                    exit
+                    exit 0
                     ;;
         deploy )
                     display_header
@@ -1612,7 +1626,6 @@ main () {
                     show_status
                     cleanup
                     exit 0
-                    # some show command
                     ;;
         erase )
                     display_header
@@ -1640,36 +1653,5 @@ main () {
 # This command starts the that sets the whole framework in motion.
 main
 
-# Either start new jobs or exit, sleep in the meantime.
-while true
-do
-    sleep 5
-    JOBS=`ps aux | grep $USER | grep -v grep | grep -v -i screen | grep ppss.sh | wc -l`
-    log DEBUG "There are $JOBS running processes. "
-    
-    get_min_jobs
-
-    if [ "$JOBS" -gt "$MIN_JOBS" ] 
-    then
-        log DEBUG "Sleeping $INTERVAL seconds." 
-        sleep $INTERVAL
-    else
-        if [ "$STOP" == "1" ] || [ ! "$PERCENT" == "100" ]
-        then
-            set_status "STOPPED"
-        elif [ "$PERCENT" == "100" ]
-        then
-            set_status "FINISHED"
-        fi
-
-        echo -en "\033[1B"
-        log INFO "There are no more running jobs, so we must be finished."
-        echo -en "\033[1B"
-        log INFO "Killing listener and remainig processes."
-        log INFO "Dying processes may display an error message."
-        kill_process
-fi
-done
-
 # Exit after all processes have finished.
 wait