diff --git a/README.md b/README.md
index 5333571..fc50c6c 100644
--- a/README.md
+++ b/README.md
@@ -40,6 +40,8 @@ Add or adjust the configuration for your collectd’s Python plugin as follows:
Address "12:34:56:78:90:ab"
SocketName "FirstSocket"
+ ReadTimeout 30
+ SuspendTime 300
Address "ab:cd:ef:13:37:42"
@@ -49,6 +51,14 @@ Add or adjust the configuration for your collectd’s Python plugin as follows:
```
+`ReadTimeout` and `SuspendTime` control what’s happening when a device is
+unavailable. If no value could be retrieved for `ReadTimeout` seconds, the
+plugin does not retry for `SuspendTime` seconds. After that, normal operation
+is resumed. This procedure ensures that an unreachable device does not block
+other devices (too often) in the current single-threaded architecture.
+
+If not specified, `ReadTimeout` is 30 seconds and `SuspendTime` is 5 minutes.
+
Make sure that everything listed in `requirements.txt` is available to the user
running collectd.
diff --git a/collectd/collectd_sem6000.py b/collectd/collectd_sem6000.py
index 76f19bb..40d2048 100755
--- a/collectd/collectd_sem6000.py
+++ b/collectd/collectd_sem6000.py
@@ -3,6 +3,7 @@
# vim: noet ts=2 sw=2 sts=2
import os
+import time
import collectd
from sem6000 import SEMSocket
@@ -25,6 +26,12 @@ def config_func(cfg):
if key in ['address', 'socketname']:
config[key] = value
+ if key == 'readtimeout':
+ config['readtimeout'] = int(value)
+
+ if key == 'suspendtime':
+ config['suspendtime'] = int(value)
+
if 'address' not in config.keys():
collectd.error('sem6000: address must be set')
return
@@ -32,7 +39,19 @@ def config_func(cfg):
if 'socketname' not in config.keys():
config['socketname'] = config['address'].replace(':', '')
- instances.append( {'config': config, 'socket': None} )
+ if 'readtimeout' not in config.keys():
+ config['readtimeout'] = 30
+
+ if 'suspendtime' not in config.keys():
+ config['suspendtime'] = 300
+
+ instances.append( {
+ 'config': config,
+ 'socket': None,
+ 'suspended': False,
+ 'lastsuccess': 0,
+ 'resumetime': 0
+ } )
def read_func():
global instances
@@ -40,6 +59,14 @@ def read_func():
for inst in instances:
config = inst['config']
+ if inst['suspended']:
+ if time.time() < inst['resumetime']:
+ continue
+ else:
+ collectd.info("sem6000: Device {} waking up.".format(config['address']))
+ inst['suspended'] = False
+ inst['lastsuccess'] = time.time()
+
try:
if inst['socket'] == None:
collectd.info("sem6000: Connecting to {}...".format(config['address']))
@@ -52,6 +79,13 @@ def read_func():
collectd.warning("sem6000: Exception caught: {}".format(e))
collectd.warning("sem6000: Restarting on next cycle...")
+ if inst['lastsuccess'] < time.time() - config['readtimeout']:
+ collectd.error("sem6000: no successful communication with {} for {:.1f} seconds. Suspending device for {:.1f} seconds.".format(
+ config['address'], config['readtimeout'], config['suspendtime']))
+
+ inst['suspended'] = True
+ inst['resumetime'] = time.time() + config['suspendtime']
+
if inst['socket'] != None:
inst['socket'].disconnect()
inst['socket'] = None
@@ -61,6 +95,8 @@ def read_func():
if socket != None and socket.voltage != 0:
collectd.debug("Uploading values for {}".format(socket.mac_address))
+ inst['lastsuccess'] = time.time()
+
val = collectd.Values(plugin = 'sem6000-{}'.format(config['socketname']))
val.type = 'voltage'