bad habits die hard

Bad Habits Die HardStaying on the Right Cassandra Path

1 Sliding back into a relational mindset

2 Benchmarking, how does this go again?

3 My client is slower than molasses in January

4 Bad operations habits

5 Q & A

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BadHabitsDieHard


Sliding back into the

relationalmindset

Sliding Back into the Relational Mindset

CQL is almost too reminiscent of SQL


I’m lazy, let’s just copy the schema


CQL is almost too reminiscent of SQL


Query-Driven Methodology, say it with me


Oh, wait, I forgot there’s no joins in Cassandra!


That’s OK, we’ll just do those client side


Oh, wait, I forgot there’s no joins in Cassandra!


Remember, denormalization is cheaper than joins



I’ve played with C* and it has indexes

Great! We’ll use them then.


Nope



Querying one partition is cheaper.

I’ve played with C* and it has indexes

Sweet! DataStax Enterprise has SparkSQL!


Great…we can use the ODBC driver just like an RDBMS!



DataStax Enterprise has SparkSQL!


Spark is OLAP not OLTP


!=

Remember:


Benchmarking

How does this go

again?


Or perhaps a

SAN?

Benchmarking, how does this go again?

Let us test on a VM!


No Cigar


Benchmarking, how does this go again?Why not select suitable hardware instead?

Test on 5 nodes

with RF=3For search or analytics use more

RAM (128GB+)

32GB RAM 8–12 CPU cores 2TB SSD


Let’s try and break it with cassandra-stress!

With only one client running, the cluster won’t do more than 1,000 tps? What gives?



Let’s try and break it with cassandra-stress!

Distributed Database = Distributed Clients



How long should we run this for?

No longer than a

sneeze.



How long do we run this for?

Aim for days or weeks.



Testing it with 100

GBs sounds great!



NO

MAKE IT STOP


Use real data volumes, not pretend ones.



My client

is slower thanMolasses in

January


Why is my Client slower than molasses in January?

1. Download DataStax Driver2. Used unlogged BATCH

statements3. Connected Client to Load

Balancer


1. Download DataStax Driver2. Use Prepared Statements

and Async Requests3. Use the DataStax Driver to

Load Balance

Why is my Client slower than molasses in January?


BadOPERATIONS

Habits


Bad Operations Habits

1. Meh Backups2. Meh Repairs3. Meh Latency on 1% of our

Ops4. Let’s add a couple nodes to

scale


Use OpsCenter

1. Backup service2. Repair service3. Capacity service4. Proactive Alerts, External

Notifications and Best Practices


Bad Operations Habits

1. Clock skew, you got it covered on that one node right?

2. Configured your Topology Strategy?

3. Set the right snitch?4. Did you just use C* as a

queue?5. Checked your versions are

the same?


NO


Good Operations Habits

1. Install & configure NTP on every node

2. NetworkTopology Strategy3. GossipingPropertyFileSnitch4. Queue? Stop misusing

Cassandra5. Upgrade strategy: rolling

upgrades, node by node


YesFeeling better?

• Free Online Training to Up Your Game• www.academy.datastax.com

• More Advanced Courses as well as Beginner• Introduction to Apache Cassandra• Cassandra Core Concepts• Operations and Performance Tuning• Data Modeling• DataStax Enterprise Search with Apache Solr• DataStax Enterprise Analytics with Apache Spark

• Seek Advice• Talk to a friendly Solutions Engineer from DataStax


Where to learn more:

http://www.academy.datastax.com/


Questions?

bad habits die hard

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