I am trying to use ycsb to carry out benchmarking of mongodb.
I have downloaded and installed mongo db as per instructions specified on YCSB MongoDB
After that I created "ycsb" named database in mongodb using below commands
1. use ycsb
2. db.createCollection("ycsb")
As specified in above link, I ran below command to load data into ycsb DB,
./bin/ycsb load mongodb -s -P workloads/workloada -p mongodb.url=mongodb://127.0.0.1:27017 -p mongodb.database=ycsb
I just wanted to check load phase execution so I have not specified other parameters. I got below log on screen,
root@pegdb2:~/ycsb-0.1.4# ./bin/ycsb load mongodb -s -P workloads/workloada -p mongodb.url=mongodb://127.0.0.1:27017 -p mongodb.database=ycsb
java -cp /root/ycsb-0.1.4/gemfire-binding/conf:/root/ycsb-0.1.4/infinispan-binding/conf:/root/ycsb-0.1.4/nosqldb-binding/conf:/root/ycsb-0.1.4/core/lib/core-0.1.4.jar:/root/ycsb-0.1.4/hbase-binding/conf:/root/ycsb-0.1.4/mongodb-binding/lib/mongodb-binding-0.1.4.jar:/root/ycsb-0.1.4/voldemort-binding/conf:/root/ycsb-0.1.4/jdbc-binding/conf com.yahoo.ycsb.Client -db com.yahoo.ycsb.db.MongoDbClient -s -P workloads/workloada -p mongodb.url=mongodb://127.0.0.1:27017 -p mongodb.database=ycsb -load
YCSB Client 0.1
Command line: -db com.yahoo.ycsb.db.MongoDbClient -s -P workloads/workloada -p mongodb.url=mongodb://127.0.0.1:27017 -p mongodb.database=ycsb -load
Loading workload...
Starting test.
new database url = 127.0.0.1:27017/ycsb
0 sec: 0 operations;
mongo connection created with 127.0.0.1:27017/ycsb
java.lang.NullPointerException
0 sec: 0 operations; [INSERT AverageLatency(us)=28568]
[OVERALL], RunTime(ms), 143.0
[OVERALL], Throughput(ops/sec), 0.0
[INSERT], Operations, 1
[INSERT], AverageLatency(us), 28568.0
[INSERT], MinLatency(us), 28568
[INSERT], MaxLatency(us), 28568
[INSERT], 95thPercentileLatency(ms), 28
[INSERT], 99thPercentileLatency(ms), 28
[INSERT], Return=1, 1
[INSERT], 0, 0
[INSERT], 1, 0
[INSERT], 2, 0
[INSERT], 3, 0
[INSERT], 4, 0
[INSERT], 5, 0
[INSERT], 6, 0
[INSERT], 7, 0
[INSERT], 8, 0
[INSERT], 9, 0
[INSERT], 10, 0
.
.
[INSERT], 999, 0
[INSERT], >1000, 0
After this step I just wanted to check whether is loaded successfully in DB or not. I checked using,
1. use ycsb
2. db.ycsb.find()
but search results were 0. It might be a very easy question but it will be helpful if someone provides me the correct way to load and verify the data in DB.
Thanks for help.
The problem was with one required parameter which I had not specified while loading the data.
mongodb.writeConcern is the parameter required while loading the data and running the workload. It should have one of following value,
-p mongodb.writeConcern=none
-p mongodb.writeConcern=strict
-p mongodb.writeConcern=normal
Generally -p mongodb.writeConcern=strict works as it keeps session open and consistent. This also stops getting NPE errors.
After loading the data in MongoDB, data can be verified in usertable table/collection using db.usertable.find() or db.usertable.count() commands.