Download as PDF, PPTX
![The Driver for Cassandra
Sample: Json Web Api
1
app.get('/user/:id', function (req, res, next){
2
var query = 'SELECT * FROM users WHERE id = ?';
3
cassandra.executeAsPrepared(query, [req.params.id], function (err, result) {
4
if (err) return next(err);
5
var row = result.rows[0];
6
//Response: expose some properties of the user
7
res.json({id: req.params.id, name: row.get('name')});
8
9
});
});](https://image.slidesharecdn.com/nodejsandcassandra-131127112319-phpapp02/85/Node-js-and-Cassandra-12-320.jpg)
![The Driver for Cassandra
Sample: Field streaming
1
app.get('/user/:id/image', function (req, res, next){
2
var query = 'SELECT id, profile_image FROM users WHERE id = ?';
3
cassandra.streamField(query, [req.params.id], function (err, row, image) {
4
if (err) return next(err);
5
//pipe the image stream to the response stream
6
image.pipe(res);
7
8
});
});](https://image.slidesharecdn.com/nodejsandcassandra-131127112319-phpapp02/85/Node-js-and-Cassandra-14-320.jpg)
![The Driver for Cassandra
Sample: Field streaming + image resizing
1
app.get('/user/:id/image', function (req, res, next){
2
var query = 'SELECT id, profile_image FROM users WHERE id = ?';
3
cassandra.streamField(query, [req.params.id], function (err, row, image) {
4
if (err) return next(err);
5
//pipe the image stream to a resizer stream
6
image.pipe(resizer).pipe(res);
7
8
});
});](https://image.slidesharecdn.com/nodejsandcassandra-131127112319-phpapp02/85/Node-js-and-Cassandra-15-320.jpg)
![The Driver for Cassandra
Sample: Json Web Api
1
app.get('/user/:id', function (req, res, next){
2
var query = 'SELECT * FROM users WHERE id = ?';
3
cassandra.executeAsPrepared(query, [req.params.id], function (err, result) {
4
if (err) return next(err);
5
var row = result.rows[0];
6
//Response: expose some properties of the user
7
res.json({id: req.params.id, name: row.get('name')});
8
9
});
});](https://image.slidesharecdn.com/nodejsandcassandra-131127112319-phpapp02/75/Node-js-and-Cassandra-12-2048.jpg)
![The Driver for Cassandra
Sample: Field streaming
1
app.get('/user/:id/image', function (req, res, next){
2
var query = 'SELECT id, profile_image FROM users WHERE id = ?';
3
cassandra.streamField(query, [req.params.id], function (err, row, image) {
4
if (err) return next(err);
5
//pipe the image stream to the response stream
6
image.pipe(res);
7
8
});
});](https://image.slidesharecdn.com/nodejsandcassandra-131127112319-phpapp02/75/Node-js-and-Cassandra-14-2048.jpg)
![The Driver for Cassandra
Sample: Field streaming + image resizing
1
app.get('/user/:id/image', function (req, res, next){
2
var query = 'SELECT id, profile_image FROM users WHERE id = ?';
3
cassandra.streamField(query, [req.params.id], function (err, row, image) {
4
if (err) return next(err);
5
//pipe the image stream to a resizer stream
6
image.pipe(resizer).pipe(res);
7
8
});
});](https://image.slidesharecdn.com/nodejsandcassandra-131127112319-phpapp02/75/Node-js-and-Cassandra-15-2048.jpg)
Uploaded byStratio
Node.js and Cassandra
This document discusses using Node.js and Cassandra for highly concurrent systems. It explains that Node.js is well-suited for I/O-bound applications with low CPU usage that require high concurrency. This is because Node.js uses an event-driven, non-blocking model that handles connections efficiently in a single thread without much overhead. The document also introduces the Cassandra driver for Node.js, which features connection pooling, load balancing, retry functions, and row/field streaming for efficiently accessing Cassandra from Node.js applications. Examples are given showing how to perform queries, stream rows and fields to responses.
More Related Content
![[245] presto 내부구조 파헤치기](https://cdn.slidesharecdn.com/ss_thumbnails/245presto-150915054242-lva1-app6891-thumbnail.jpg?width=600ounds&width=560&fit=bounds)
Similar to Node.js and Cassandra
![[Strata] Sparkta](https://cdn.slidesharecdn.com/ss_thumbnails/stratasparktav3-150507092440-lva1-app6891-thumbnail.jpg?width=600ounds&width=560&fit=bounds)
![UiPath Automation Suite Installation (Hands-On) [2/3]](https://cdn.slidesharecdn.com/ss_thumbnails/automationsuitecommunitysession2-251015095633-a6d862f1-thumbnail.jpg?width=600ounds&width=560&fit=bounds)
Node.js and Cassandra
- 1. Node.js and Cassandra Forhighly concurrent systems
- 2. Software as aservice Most common scenario • • • I/O Bound o db o other services o file system Low CPU usage Peaks and valleys
- 3.
- 4. Why Node.js Event-based • • • • Single threaded Minimumoverhead per connection Predictable amount of memory under load Apache / IIS vs Nginx: Process-based vs event-loop Everything runs in parallel except your code
- 5. Why Node.js Event-based: Apachevs Nginx source webfaction.com
- 6. Why Node.js Async I/O • • UsesOS network interfaces + fixed thread pool Time spent: db connections / files
- 7. Why Node.js Javascript: Closures • • • • CPS:Continuation passing style The scope of the outer function -> inner function Javascript: Functional / Dynamic / Object oriented ... packet manager / os community / V8 / ubiquitous...
- 8. Why Node.js Stream everything • • • • Avoidbuffering HTTP: Chunked requests and responses TCP: Chunks readable in a stream Stream Piping (UNIX like)
- 9. The Driver forCassandra
- 10. The Driver forCassandra Features • • • • • Connection pooling to multiple hosts Load balancing Automatic failover / retry Row and field streaming Queuing: Concurrent connecting / preparing
- 11. The Driver forCassandra App Cassandra nodes A G E D C F H B
- 12. The Driver forCassandra Sample: Json Web Api 1 app.get('/user/:id', function (req, res, next){ 2 var query = 'SELECT * FROM users WHERE id = ?'; 3 cassandra.executeAsPrepared(query, [req.params.id], function (err, result) { 4 if (err) return next(err); 5 var row = result.rows[0]; 6 //Response: expose some properties of the user 7 res.json({id: req.params.id, name: row.get('name')}); 8 9 }); });
- 13. The Driver forCassandra How row streaming works Readable stream Transform stream Transform stream Socket Protocol Parser Chunks Heade r and body chunk s Client Row
- 14. The Driver forCassandra Sample: Field streaming 1 app.get('/user/:id/image', function (req, res, next){ 2 var query = 'SELECT id, profile_image FROM users WHERE id = ?'; 3 cassandra.streamField(query, [req.params.id], function (err, row, image) { 4 if (err) return next(err); 5 //pipe the image stream to the response stream 6 image.pipe(res); 7 8 }); });
- 15. The Driver forCassandra Sample: Field streaming + image resizing 1 app.get('/user/:id/image', function (req, res, next){ 2 var query = 'SELECT id, profile_image FROM users WHERE id = ?'; 3 cassandra.streamField(query, [req.params.id], function (err, row, image) { 4 if (err) return next(err); 5 //pipe the image stream to a resizer stream 6 image.pipe(resizer).pipe(res); 7 8 }); });
- 16. Moving forward Next features • • Multipledata centers support. Cassandra query tracing Contribute! :)
- 17. Thanks! Jorge Bay Gondra @jorgebg [email protected] github.com/jorgebay/node-cassandra-cql npminstall node-cassandra-cql
- 18. A Design Frameworkfor Highly Concurrent Systems by Matt Welsh, Steven D. Gribble, Eric A. Brewer, and David Culler @ UC Berkeley Concurrency is not Parallelism (it's better) by Rob Pike @Google Go lang How the single threaded non blocking IO model works in Node.js References and further reading