当statsd发送超量的metrics到graphite中，graphite单节点无法负载的情况，可以使用consistent-hashing的模式来将数据分片到backend中。同样的consistent-hashing模式下可以自动剔除／加入节点。
官方文档：
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 carbon-relay.py serves two distinct purposes: replication and sharding. When running with RELAY_METHOD = rules, a carbon-relay.py instance can run in place of a carbon-cache.py server and relay all incoming metrics to multiple backend carbon-cache.py‘s running on different ports or hosts. In RELAY_METHOD = consistent-hashing mode, a DESTINATIONS setting defines a sharding strategy across multiple carbon-cache.py backends. The same consistent hashing list can be provided to the graphite webapp via CARBONLINK_HOSTS to spread reads across the multiple backends. 本例模拟一个双后端的carbon-cache instance.单机器运行,使用carbon-cache.py 的instance功能 config文件： #####carbon.conf [cache:a] LINE_RECEIVER_PORT = 2203 PICKLE_RECEIVER_PORT = 2204 CACHE_QUERY_PORT = 7102 LOCAL_DATA_DIR = /opt/g raphite/storage/ whisper_a/ [cache:b] LINE_RECEIVER_PORT = 2205 PICKLE_RECEIVER_PORT = 2206 CACHE_QUERY_PORT = 7202 LOCAL_DATA_DIR = /opt/g raphite/storage/ whisper_b/ [relay] LINE_RECEIVER_INTERFACE = 0.0 .0.0 LINE_RECEIVER_PORT = 2003 PICKLE_RECEIVER_INTERFACE = 0.0 .0.0 PICKLE_RECEIVER_PORT = 2004 DESTINATIONS = 127.0 .0.1 :2204 :a, 127.0 .0.1 :2206 :b 启动服务： 启动instance:a xmx@xiemx-test:/opt/g raphisudo ./carbon-cache.py --instance=a --config=/ opt/graphite/ conf/carbon.conf start Starting carbon-cache (instance a) 启动instance:b xmx@xiemx-test:/opt/g raphite/bin$ sudo ./ carbon-cache.py --instance=b --config=/opt/g raphite/conf/ carbon.conf start Starting carbon-cache (instance b) 启动relay: xmx@xiemx-test:/opt/g raphite/conf$ sudo / opt/graphite/ bin/carbon-relay.py --debug --config=/ opt/graphite/ conf/carbon.conf start Starting carbon-relay (instance a) 08 /09/ 2017 16 :02 :16 :: [console] Using sorted write strategy for cache08 /09/ 2017 16 :02 :16 :: [clients] connecting to carbon daemon at 127.0 .0.1 :2204 :a08 /09/ 2017 16 :02 :16 :: [clients] connecting to carbon daemon at 127.0 .0.1 :2206 :b08 /09/ 2017 16 :02 :16 :: [console] twistd 16.4 .1 (/usr/ bin/python 2.7 .6 ) starting up.08 /09/ 2017 16 :02 :16 :: [console] reactor class : twisted.internet.epollreactor.EPollReactor.08 /09/ 2017 16 :02 :16 :: [console] Starting factory CarbonClientFactory(127.0 .0.1 :2206 :b)08 /09/ 2017 16 :02 :16 :: [clients] CarbonClientFactory(127.0 .0.1 :2206 :b)::startedConnecting (127.0 .0.1 :2206 )08 /09/ 2017 16 :02 :16 :: [console] Starting factory CarbonClientFactory(127.0 .0.1 :2204 :a)08 /09/ 2017 16 :02 :16 :: [clients] CarbonClientFactory(127.0 .0.1 :2204 :a)::startedConnecting (127.0 .0.1 :2204 )08 /09/ 2017 16 :02 :16 :: [console] CarbonReceiverFactory starting on 2003 08 /09/ 2017 16 :02 :16 :: [console] Starting factory 08 /09/ 2017 16 :02 :16 :: [console] CarbonReceiverFactory starting on 2004 08 /09/ 2017 16 :02 :16 :: [console] Starting factory 08 /09/ 2017 16 :02 :16 :: [clients] CarbonClientProtocol(127.0 .0.1 :2206 :b)::connectionMade08 /09/ 2017 16 :02 :16 :: [clients] CarbonClientFactory(127.0 .0.1 :2206 :b)::connectionMade (CarbonClientProtocol(127.0 .0.1 :2206 :b))08 /09/ 2017 16 :02 :16 :: [clients] Destination is up: 127.0 .0.1 :2206 :b08 /09/ 2017 16 :02 :16 :: [clients] CarbonClientProtocol(127.0 .0.1 :2204 :a)::connectionMade08 /09/ 2017 16 :02 :16 :: [clients] CarbonClientFactory(127.0 .0.1 :2204 :a)::connectionMade (CarbonClientProtocol(127.0 .0.1 :2204 :a))08 /09/ 2017 16 :02 :16 :: [clients] Destination is up: 127.0 .0.1 :2204 :a
测试：
模拟5个客户端同时发送100个key
模拟node掉线重连
graphite-web数据聚合展示
1 2 3 4 5 修改local_settings.py CARBONLINK_HOSTS = ["127.0.0.1:7102:a" , "127.0.0.1:7202:b" ] 启动django sudo PYTHONPATH=/opt/graphite/webapp django-admin.py runserver 0.0 .0.0 :5000 --settings
