A series of tools for ZooKeeper
Scripts
zkServer.sh
A command for the operations for the ZooKeeper server.
```bash Usage: ./zkServer.sh {start|start-foreground|stop|version|restart|status|upgrade|print-cmd}
start the server
./zkServer.sh start
start the server in the foreground for debugging
./zkServer.sh start-foreground
stop the server
./zkServer.sh stop
restart the server
./zkServer.sh restart
show the status,mode,role of the server
./zkServer.sh status JMX enabled by default Using config: /data/software/zookeeper/conf/zoo.cfg Mode: standalone
Deprecated
./zkServer.sh upgrade
print the parameters of the start-up
./zkServer.sh print-cmd
show the version of the ZooKeeper server
./zkServer.sh version Apache ZooKeeper, version 3.6.0-SNAPSHOT 06/11/2019 05:39 GMT
```
The status command establishes a client connection to the server to execute diagnostic commands. When the ZooKeeper cluster is started in client SSL only mode (by omitting the clientPort from the zoo.cfg), then additional SSL related configuration has to be provided before using the ./zkServer.sh status command to find out if the ZooKeeper server is running. An example:
CLIENT_JVMFLAGS="-Dzookeeper.clientCnxnSocket=org.apache.zookeeper.ClientCnxnSocketNetty -Dzookeeper.ssl.trustStore.location=/tmp/clienttrust.jks -Dzookeeper.ssl.trustStore.password=password -Dzookeeper.ssl.keyStore.location=/tmp/client.jks -Dzookeeper.ssl.keyStore.password=password -Dzookeeper.client.secure=true" ./zkServer.sh status
zkCli.sh
Look at the ZooKeeperCLI
zkEnv.sh
The environment setting for the ZooKeeper server
```bash
the setting of log property
ZOO_LOG_DIR: the directory to store the logs ZOO_LOG4J_PROP: the level of logs to print ```
zkCleanup.sh
Clean up the old snapshots and transaction logs.
```bash Usage: * args dataLogDir [snapDir] -n count * dataLogDir -- path to the txn log directory * snapDir -- path to the snapshot directory * count -- the number of old snaps/logs you want to keep, value should be greater than or equal to 3
Keep the latest 5 logs and snapshots
./zkCleanup.sh -n 5 ```
zkTxnLogToolkit.sh
TxnLogToolkit is a command line tool shipped with ZooKeeper which is capable of recovering transaction log entries with broken CRC.
Running it without any command line parameters or with the -h,--help argument, it outputs the following help page:
$ bin/zkTxnLogToolkit.sh
usage: TxnLogToolkit [-dhrv] txn_log_file_name
-d,--dump Dump mode. Dump all entries of the log file. (this is the default)
-h,--help Print help message
-r,--recover Recovery mode. Re-calculate CRC for broken entries.
-v,--verbose Be verbose in recovery mode: print all entries, not just fixed ones.
-y,--yes Non-interactive mode: repair all CRC errors without asking
The default behaviour is safe: it dumps the entries of the given transaction log file to the screen: (same as using -d,--dump parameter)
$ bin/zkTxnLogToolkit.sh log.100000001
ZooKeeper Transactional Log File with dbid 0 txnlog format version 2
4/5/18 2:15:58 PM CEST session 0x16295bafcc40000 cxid 0x0 zxid 0x100000001 createSession 30000
CRC ERROR - 4/5/18 2:16:05 PM CEST session 0x16295bafcc40000 cxid 0x1 zxid 0x100000002 closeSession null
4/5/18 2:16:05 PM CEST session 0x16295bafcc40000 cxid 0x1 zxid 0x100000002 closeSession null
4/5/18 2:16:12 PM CEST session 0x26295bafcc90000 cxid 0x0 zxid 0x100000003 createSession 30000
4/5/18 2:17:34 PM CEST session 0x26295bafcc90000 cxid 0x0 zxid 0x200000001 closeSession null
4/5/18 2:17:34 PM CEST session 0x16295bd23720000 cxid 0x0 zxid 0x200000002 createSession 30000
4/5/18 2:18:02 PM CEST session 0x16295bd23720000 cxid 0x2 zxid 0x200000003 create '/andor,#626262,v{s{31,s{'world,'anyone}}},F,1
EOF reached after 6 txns.
There's a CRC error in the 2nd entry of the above transaction log file. In dump mode, the toolkit only prints this information to the screen without touching the original file. In recovery mode (-r,--recover flag) the original file still remains untouched and all transactions will be copied over to a new txn log file with ".fixed" suffix. It recalculates CRC values and copies the calculated value, if it doesn't match the original txn entry. By default, the tool works interactively: it asks for confirmation whenever CRC error encountered.
$ bin/zkTxnLogToolkit.sh -r log.100000001
ZooKeeper Transactional Log File with dbid 0 txnlog format version 2
CRC ERROR - 4/5/18 2:16:05 PM CEST session 0x16295bafcc40000 cxid 0x1 zxid 0x100000002 closeSession null
Would you like to fix it (Yes/No/Abort) ?
Answering Yes means the newly calculated CRC value will be outputted to the new file. No means that the original CRC value will be copied over. Abort will abort the entire operation and exits. (In this case the ".fixed" will not be deleted and left in a half-complete state: contains only entries which have already been processed or only the header if the operation was aborted at the first entry.)
$ bin/zkTxnLogToolkit.sh -r log.100000001
ZooKeeper Transactional Log File with dbid 0 txnlog format version 2
CRC ERROR - 4/5/18 2:16:05 PM CEST session 0x16295bafcc40000 cxid 0x1 zxid 0x100000002 closeSession null
Would you like to fix it (Yes/No/Abort) ? y
EOF reached after 6 txns.
Recovery file log.100000001.fixed has been written with 1 fixed CRC error(s)
The default behaviour of recovery is to be silent: only entries with CRC error get printed to the screen. One can turn on verbose mode with the -v,--verbose parameter to see all records. Interactive mode can be turned off with the -y,--yes parameter. In this case all CRC errors will be fixed in the new transaction file.
zkSnapShotToolkit.sh
Dump a snapshot file to stdout, showing the detailed information of the each zk-node.
```bash
help
./zkSnapShotToolkit.sh /usr/bin/java USAGE: SnapshotFormatter [-d|-json] snapshot_file -d dump the data for each znode -json dump znode info in json format
show the each zk-node info without data content
./zkSnapShotToolkit.sh /data/zkdata/version-2/snapshot.fa01000186d /zk-latencies_4/session_946 cZxid = 0x00000f0003110b ctime = Wed Sep 19 21:58:22 CST 2018 mZxid = 0x00000f0003110b mtime = Wed Sep 19 21:58:22 CST 2018 pZxid = 0x00000f0003110b cversion = 0 dataVersion = 0 aclVersion = 0 ephemeralOwner = 0x00000000000000 dataLength = 100
[-d] show the each zk-node info with data content
./zkSnapShotToolkit.sh -d /data/zkdata/version-2/snapshot.fa01000186d /zk-latencies2/session_26229 cZxid = 0x00000900007ba0 ctime = Wed Aug 15 20:13:52 CST 2018 mZxid = 0x00000900007ba0 mtime = Wed Aug 15 20:13:52 CST 2018 pZxid = 0x00000900007ba0 cversion = 0 dataVersion = 0 aclVersion = 0 ephemeralOwner = 0x00000000000000 data = eHh4eHh4eHh4eHh4eA==
[-json] show the each zk-node info with json format
./zkSnapShotToolkit.sh -json /data/zkdata/version-2/snapshot.fa01000186d [[1,0,{"progname":"SnapshotFormatter.java","progver":"0.01","timestamp":1559788148637},[{"name":"/","asize":0,"dsize":0,"dev":0,"ino":1001},[{"name":"zookeeper","asize":0,"dsize":0,"dev":0,"ino":1002},{"name":"config","asize":0,"dsize":0,"dev":0,"ino":1003},[{"name":"quota","asize":0,"dsize":0,"dev":0,"ino":1004},[{"name":"test","asize":0,"dsize":0,"dev":0,"ino":1005},{"name":"zookeeper_limits","asize":52,"dsize":52,"dev":0,"ino":1006},{"name":"zookeeper_stats","asize":15,"dsize":15,"dev":0,"ino":1007}]]],{"name":"test","asize":0,"dsize":0,"dev":0,"ino":1008}]] ```
Testing
Jepsen Test
A framework for distributed systems verification, with fault injection. Jepsen has been used to verify everything from eventually-consistent commutative databases to linearizable coordination systems to distributed task schedulers. more details can be found in jepsen-io
Running the Dockerized Jepsen is the simplest way to use the Jepsen.
Installation:
```bash git clone git@github.com:jepsen-io/jepsen.git cd docker
maybe a long time for the first init.
./up.sh
docker ps to check one control node and five db nodes are up
docker ps CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES 8265f1d3f89c docker_control "/bin/sh -c /init.sh" 9 hours ago Up 4 hours 0.0.0.0:32769->8080/tcp jepsen-control 8a646102da44 docker_n5 "/run.sh" 9 hours ago Up 3 hours 22/tcp jepsen-n5 385454d7e520 docker_n1 "/run.sh" 9 hours ago Up 9 hours 22/tcp jepsen-n1 a62d6a9d5f8e docker_n2 "/run.sh" 9 hours ago Up 9 hours 22/tcp jepsen-n2 1485e89d0d9a docker_n3 "/run.sh" 9 hours ago Up 9 hours 22/tcp jepsen-n3 27ae01e1a0c5 docker_node "/run.sh" 9 hours ago Up 9 hours 22/tcp jepsen-node 53c444b00ebd docker_n4 "/run.sh" 9 hours ago Up 9 hours 22/tcp jepsen-n4 ```
Running & Test
```bash
Enter into the container:jepsen-control
docker exec -it jepsen-control bash
Test
cd zookeeper && lein run test --concurrency 10
See something like the following to assert that ZooKeeper has passed the Jepsen test
INFO [2019-04-01 11:25:23,719] jepsen worker 8 - jepsen.util 8 :ok :read 2 INFO [2019-04-01 11:25:23,722] jepsen worker 3 - jepsen.util 3 :invoke :cas [0 4] INFO [2019-04-01 11:25:23,760] jepsen worker 3 - jepsen.util 3 :fail :cas [0 4] INFO [2019-04-01 11:25:23,791] jepsen worker 1 - jepsen.util 1 :invoke :read nil INFO [2019-04-01 11:25:23,794] jepsen worker 1 - jepsen.util 1 :ok :read 2 INFO [2019-04-01 11:25:24,038] jepsen worker 0 - jepsen.util 0 :invoke :write 4 INFO [2019-04-01 11:25:24,073] jepsen worker 0 - jepsen.util 0 :ok :write 4 ............................................................................... Everything looks good! ヽ(‘ー`)ノ
```
Reference: read this blog to learn more about the Jepsen test for the Zookeeper.