Increase collection interval for GlusterFS

This change increases the default collection interval for GlusterFS
because it doesn't cope well with concurrent client requests.

Change-Id: I500e8785bcb22aa61612e5a17a2a60bb3b99eed0
diff --git a/collectd/files/plugin/collectd_glusterfs.py b/collectd/files/plugin/collectd_glusterfs.py
index 75daf4b..6d413df 100644
--- a/collectd/files/plugin/collectd_glusterfs.py
+++ b/collectd/files/plugin/collectd_glusterfs.py
@@ -23,6 +23,9 @@
 
 NAME = 'glusterfs'
 GLUSTER_BINARY = '/usr/sbin/gluster'
+# Increase the default collection interval because GlusterFS doesn't cope well
+# with concurrent client requests
+INTERVAL = 120
 
 peer_re = re.compile(r'^Hostname: (?P<peer>.+)$', re.MULTILINE)
 state_re = re.compile(r'^State: (?P<state>.+)$', re.MULTILINE)
@@ -59,6 +62,7 @@
     def __init__(self, *args, **kwargs):
         super(GlusterfsPlugin, self).__init__(*args, **kwargs)
         self.plugin = NAME
+        self.interval = INTERVAL
 
     def itermetrics(self):
         # Collect peers' metrics
@@ -237,4 +241,4 @@
 else:
     collectd.register_init(init_callback)
     collectd.register_config(config_callback)
-    collectd.register_read(read_callback)
+    collectd.register_read(read_callback, INTERVAL)