From 650838406000be4aa04ffb59b9033b568152f3a3 Mon Sep 17 00:00:00 2001
From: Thomas Bechtold <tbechtold@suse.com>
Date: Tue, 29 Jan 2019 10:31:36 +0100
Subject: [PATCH] Change default for [kafka]num_processors to 1

Currently the default for [kafka]num_processors is 0. This can lead to
the situation where monasca-persister starts but nothing happens
because no processes are started.
This can happen very easy in the default configuration where the
"num_processors" value in the different
sections ([kafka_alarm_history], [kafka_events], [kafka_metrics]) is
set to:

num_processors = $kafka.num_processors

which means that in the default case, 0 processes are started.
This is fixed now because the default for [kafka]num_processors is now
1.

Change-Id: I2c8ed56bbe91648543044201d7b6320f88a724c7
---
 monasca_persister/conf/kafka_common.py | 2 +-
 monasca_persister/persister.py         | 4 ++++
 2 files changed, 5 insertions(+), 1 deletion(-)

diff --git a/monasca_persister/conf/kafka_common.py b/monasca_persister/conf/kafka_common.py
index 534d5926..1217b075 100644
--- a/monasca_persister/conf/kafka_common.py
+++ b/monasca_persister/conf/kafka_common.py
@@ -42,7 +42,7 @@ kafka_common_opts = [
                default=32768),
     cfg.IntOpt('num_processors',
                help='Number of processes spawned by persister',
-               default=0)
+               default=1)
 ]
 
 kafka_common_group = cfg.OptGroup(name='kafka',
diff --git a/monasca_persister/persister.py b/monasca_persister/persister.py
index c7bfd0c3..637abbaf 100644
--- a/monasca_persister/persister.py
+++ b/monasca_persister/persister.py
@@ -102,6 +102,10 @@ def prepare_processes(conf, repo_driver):
         for proc in range(0, conf.num_processors):
             processors.append(multiprocessing.Process(
                 target=start_process, args=(repository, conf)))
+    else:
+        LOG.warning("Number of processors (num_processors) is {}".format(
+            conf.num_processors))
+
 
 def main():
     """Start persister."""