ZKTraffic

Table of Contents

• tl;dr
• Installing
• What is ZKTraffic?
• Contributing and Testing
• More tools!
• OS X
• Dependencies

tl;dr

ZooKeeper protocol analyzer and stats gathering daemon

Installing

You can install ZKTraffic via pip:

.. code-block:: bash

$ pip install zktraffic

Or run it from source (if you have the dependencies installed, see below):

.. code-block:: bash

$ git clone https://github.com/twitter/zktraffic.git $ cd zktraffic $ sudo ZKTRAFFIC_SOURCE=1 bin/zk-dump --iface=eth0

To get a quick count of requests by path:

.. code-block:: bash

$ sudo ZKTRAFFIC_SOURCE=1 bin/zk-dump --iface=eth0 --count-requests 10000 --sort-by path / 1749 /services/prod/search 846 /configs/teleportation/features 843

Or by type:

.. code-block:: bash

$ sudo ZKTRAFFIC_SOURCE=1 bin/zk-dump --iface=eth0 --count-requests 10000 --sort-by type GetChildrenRequest 9044 ExistsRequest 958

You can also measure latencies by path (avg, p95 and p99):

.. code-block:: bash

$ sudo ZKTRAFFIC_SOURCE=1 bin/zk-dump --measure-latency 1000 --group-by path --aggregation-depth 2 --sort-by p99 path avg p95 p99

---

/party/services 0.000199077 0.00048846 0.00267805 /party 0.000349498 0.00136839 0.00201204 /party/configs 0.000157728 0.00036664 0.00122663

Or by type:

.. code-block:: bash

$ sudo ZKTRAFFIC_SOURCE=1 bin/zk-dump --measure-latency 1000 --group-by type --sort-by p99 type avg p95 p99

---

CreateEphemeralRequest 0.000735009 0.000978041 0.0032404 GetChildrenRequest 0.000182547 0.000453258 0.00220628 ExistsRequest 0.000162728 0.000430155 0.000862937

Or by client:

.. code-block:: bash

$ sudo ZKTRAFFIC_SOURCE=1 bin/zk-dump --measure-latency 1000 --group-by client --sort-by p99 client avg p95 p99

---

10.0.1.3:44308 0.000735009 0.000978041 0.0032404 10.0.1.6:34305 0.000182547 0.000453258 0.00220628 10.0.1.9:36110 0.000162728 0.000430155 0.000862937

Or use the stats gathering daemon:

.. code-block:: bash

$ sudo ZKTRAFFIC_SOURCE=1 bin/zk-stats-daemon --iface=eth0 --http-port=9090

Or you can build PEX files — from the source — for any of the available tools:

.. code-block:: bash

$ pip install pex

zk-dump

$ pex -v -e zktraffic.cli.zk -o zk-dump.pex .

zk-stats-daemon

$ pex -v -e zktraffic.cli.stats_daemon -o stats-daemon.pex .

zab-dump

$ pex -v -e zktraffic.cli.zab -o zab-dump.pex .

fle-dump

$ pex -v -e zktraffic.cli.fle -o fle-dump.pex .

More info about PEX here.

What is ZKTraffic?

An {iptraf,top}-esque traffic monitor for ZooKeeper. Right now it exports per-path (and global) stats. Eventually it'll be made to export per-user stats too.

It has a front-end, zk-dump, that can be used in interactive mode to dump traffic:

# need root or CAP_NET_ADMIN & CAP_NET_RAW
$ sudo zk-dump --iface eth0
21:08:05:991542 ConnectRequest(ver=0, zxid=0, timeout=10000, session=0x0, readonly=False, client=127.0.0.1:50049)
————————►21:08:06:013513 ConnectReply(ver=0, timeout=10000, session=0x148cf0aedc60000, readonly=False, client=127.0.0.1:50049)
21:08:07:432361 ExistsRequest(xid=1, path=/, watch=False, size=14, client=127.0.0.1:50049)
————————►21:08:07:447353 ExistsReply(xid=1, zxid=31, error=0, client=127.0.0.1:50049)
21:08:07:448033 GetChildrenRequest(xid=2, path=/, watch=False, size=14, client=127.0.0.1:50049)
————————►21:08:07:456169 GetChildrenReply(xid=2, zxid=31, error=0, count=1, client=127.0.0.1:50049)
...

Or, it can work in daemon mode from which it exposes HTTP/JSON endpoints with stats that can be fed into your favourite data collection system:

.. code-block:: bash

$ sudo zk-stats-daemon.pex --app_daemonize --aggregation-depth=5

Wait for 1 min and:

$ sleep 60 && curl http://localhost:7070/json/paths | python -mjson.tool { "ConnectRequest": 2, "ConnectRequestBytes": 90, "CreateRequest/configs": 2, "CreateRequest/configs/server": 2, "CreateRequest/discovery": 2, "CreateRequest/discovery/hosts": 2, "CreateRequest/discovery/services": 2, "CreateRequestBytes/configs": 110, "CreateRequestBytes/configs/server": 124, "CreateRequestBytes/discovery": 114, "CreateRequestBytes/discovery/hosts": 126, "CreateRequestBytes/discovery/services": 132, "ExistsRequest/": 1574, "ExistsRequest/configs": 3, "ExistsRequest/configs/server": 2, "ExistsRequest/discovery": 4, "ExistsRequest/discovery/hosts": 2, "ExistsRequest/discovery/services": 2, "ExistsRequestBytes/": 22036, "ExistsRequestBytes/configs": 63, "ExistsRequestBytes/configs/server": 56, "ExistsRequestBytes/discovery": 92, "ExistsRequestBytes/discovery/hosts": 58, "ExistsRequestBytes/discovery/services": 64, "GetChildrenRequest/configs": 1285, "GetChildrenRequest/configs/server": 1242, "GetChildrenRequest/discovery": 1223, "GetChildrenRequest/discovery/hosts": 1250, "GetChildrenRequest/discovery/services": 1222, "GetChildrenRequest/zookeeper/config": 1285, "GetChildrenRequest/zookeeper/quota/limits": 1228, "GetChildrenRequest/zookeeper/quota/limits/by-path": 1269, "GetChildrenRequest/zookeeper/quota/limits/global": 1230, "GetChildrenRequest/zookeeper/quota/stats/by-path": 1222, "GetChildrenRequestBytes/discovery/hosts": 36250, "GetChildrenRequestBytes/discovery/services": 39104, "GetChildrenRequestBytes/zookeeper/config": 38550, "GetChildrenRequestBytes/zookeeper/quota/limits": 44208, "GetChildrenRequestBytes/zookeeper/quota/limits/by-path": 55836, "GetChildrenRequestBytes/zookeeper/quota/limits/global": 52890, "GetChildrenRequestBytes/zookeeper/quota/limits/slices": 51815, "GetChildrenRequestBytes/zookeeper/quota/stats": 42630, "GetChildrenRequestBytes/zookeeper/quota/stats/by-path": 52546, "GetChildrenRequestBytes/zookeeper/quota/stats/global": 50568, "reads/": 2761, "reads/configs": 1288, "reads/configs/server": 1244, "reads/discovery": 1227, "reads/discovery/hosts": 1252, "reads/discovery/services": 1224, "reads/zookeeper/config": 1285, "reads/zookeeper/quota/limits": 1228, "reads/zookeeper/quota/limits/by-path": 1269, "reads/zookeeper/quota/limits/global": 1230, "readsBytes/": 38654, "readsBytes/discovery/services": 39168, "readsBytes/zookeeper/config": 38550, "readsBytes/zookeeper/quota/limits": 44208, "readsBytes/zookeeper/quota/limits/by-path": 55836, "readsBytes/zookeeper/quota/limits/global": 52890, "readsBytes/zookeeper/quota/limits/slices": 51815, "readsBytes/zookeeper/quota/stats": 42630, "readsBytes/zookeeper/quota/stats/by-path": 52546, "readsBytes/zookeeper/quota/stats/global": 50568, "total/readBytes": 655586, "total/reads": 21251, "total/writeBytes": 606, "total/writes": 10, "writes/": 0, "writes/configs": 2, "writes/configs/server": 2, "writes/discovery": 2, "writes/discovery/hosts": 2, "writes/discovery/services": 2, "writesBytes/": 0, "writesBytes/configs": 110, "writesBytes/configs/server": 124, "writesBytes/discovery": 114, "writesBytes/discovery/hosts": 126, "writesBytes/discovery/services": 132 }

Other relevant endpoints for stats are:

• /json/ips: top-N per-ip stats
• /json/auths: per-auth stats
• /json/auths-dump: a full dump of known auths
• /json/info: process uptime and introspection info
• /threads: stacks for all threads

Contributing and Testing

Please see CONTRIBUTING.md.

More tools!

Along with zk-dump and zk-stats-daemon, you can find fle-dump which allows you to inspect FastLeaderElection traffic (i.e.: the protocol by which ZooKeeper decides who will lead and the mechanism by which the leader is subsequently discovered):

.. code-block:: bash

$ sudo fle-dump --iface eth0 -c Notification( timestamp=00:57:12:593254, src=10.0.0.1:32938, dst=10.0.0.2:3888, state=following, leader=3, zxid=0, election_epoch=0, peer_epoch=0, config= server.0=10.0.0.1:2889:3888:participant;0.0.0.0:2181 server.1=10.0.0.2:2889:3888:participant;0.0.0.0:2181 server.2=10.0.0.3:2889:3888:participant;0.0.0.0:2181 server.3=10.0.0.4:2889:3888:participant;0.0.0.0:2181 server.4=10.0.0.5:2889:3888:participant;0.0.0.0:2181 version=10010d4d6 ) Notification( timestamp=00:57:12:595525, src=10.0.0.2:3888, dst=10.0.0.1:32938, state=looking, leader=1, zxid=4296326153, election_epoch=1, peer_epoch=1, config= server.0=10.0.0.1:2889:3888:participant;0.0.0.0:2181 server.1=10.0.0.2:2889:3888:participant;0.0.0.0:2181 server.2=10.0.0.3:2889:3888:participant;0.0.0.0:2181 server.3=10.0.0.4:2889:3888:participant;0.0.0.0:2181 server.4=10.0.0.5:2889:3888:participant;0.0.0.0:2181 version=10010d4d6 ) ...

Note: for initial messages to be visible you'll need the patch available at ZOOKEEPER-2098, if you are using ZooKeeper prior to ZooKeeper 3.5.1-rc2.

Note: if you are using Linux 3.14 or later, you'll need to disable TCP Auto Corking by running echo 0 > /proc/sys/net/ipv4/tcp_autocorking.

If you are interested in debugging ZAB (ZooKeeper Atomic Broadcast protocol), you can use zab-dump:

.. code-block:: bash

$ sudo zab-dump --iface eth0

Request( cxid=6, dst=10.0.0.1:2889, length=112, req_type=CreateRequest, session_id=0x34e4d23b0d70001, src=10.0.0.2:48604, timestr=22:54:31:995353, zxid=-1, ) Proposal( cxid=6, dst=10.0.0.2:48603, length=110, session_id=0x34e4d23b0d70001, src=10.0.0.1:2889, timestr=22:54:31:995753, txn_time=1435816471995, txn_type=CreateRequest, txn_zxid=8589934619, zxid=8589934619, ) Proposal( cxid=6, dst=10.0.0.1:48604, length=110, session_id=0x34e4d23b0d70001, src=10.0.0.1:2889, timestr=22:54:31:995755, txn_time=1435816471995, txn_type=CreateRequest, txn_zxid=8589934619, zxid=8589934619, ) Proposal( cxid=6, dst=10.0.0.3:48605, length=110, session_id=0x34e4d23b0d70001, src=10.0.0.1:2889, timestr=22:54:31:995770, txn_time=1435816471995, txn_type=CreateRequest, txn_zxid=8589934619, zxid=8589934619, ) Ack( dst=10.0.0.1:2889, length=20, src=10.0.0.1:48603, timestr=22:54:31:996068, zxid=8589934619, ) Ack( dst=10.0.0.1:2889, length=20, src=10.0.0.1:48604, timestr=22:54:31:996316, zxid=8589934619, ) Ack( dst=10.0.0.1:2889, length=20, src=10.0.0.1:48604, timestr=22:54:31:996318, zxid=8589934619, ) Commit( dst=10.0.0.1:48603, length=20, src=10.0.0.1:2889, timestr=22:54:31:996193, zxid=8589934619, ) Commit( dst=10.0.0.2:48604, length=20, src=10.0.0.1:2889, timestr=22:54:31:996195, zxid=8589934619, ) Commit( dst=10.0.0.2:48605, length=20, src=10.0.0.1:2889, timestr=22:54:31:996442, zxid=8589934619, )

OS X

Although no one has tried running this on OS X in production, it can be used for some parts of development and unit testing. If you are running on OS X, please run the following to install the correct dependencies:

.. code-block:: bash

$ pip install -r ./osx_requirements.txt

Dependencies

• Python 2.7 (Py3K soon)
• ansicolors
• dpkt-fix
• hexdump
• psutil>=2.1.0
• scapy==2.4.2
• six
• twitter.common.app
• twitter.common.collections
• twitter.common.exceptions
• twitter.common.http
• twitter.common.log