Cache hcm-topdev

CACHE
Cách build hệ thống
đáp ứng truy cập cao
Châu Nguyễn Nhật Thanh
Head of Game Backend and Cloud
VNG Corp.

Content
Client Internet
1
2
3
4
Server
Kernel
App
Server
6
7
8
5
9

How to scale
● Optimize at node
– Maximize the performances at node
● Scale to multiples nodes
– How to scale ?
● Scale UP
● Scale OUT

1.Client Problems
Client Internet
1
2
3
4
Server
Kernel
App
Server
6
7
8
5
9

1. Client Problems
● Web browser (HTTP)
– Static contents: js, css , image, video
– JS, CSS, image:
● minify, merge
● Compress header
– Caching:
● Expires header
● Local storage
● JS caching

1. Client Problems
● Mobile client
– Local storage
– In app resources bundle

1. Client Problems
● Tools
– Profiling:
● Chrome dev tools
– Minifying:
● Webpack, gulp, elixir (Laravel)
– File serving:
● Nginx

1. Client Problems
● Profiling

1. Client Problems
● Minifying
– gulp –production
● File serving with expire header
location ~* .(?:ico|css|js|gif|jpe?g|png)$ {
expires 30d;
add_header Pragma public;
add_header Cache-Control "public";
}

2. Client to ISP
Client Internet
1
2
3
4
Server
Kernel
App
Server
6
7
8
5
9

2. Client to ISP
● CDN (Content Delivery Network)
– Redirect (302)
– DNS server
● Content in ISP DC
● Return IP of ISP near your devices

3.ISP Problem
Client Internet
1
2
3
4
Server
Kernel
App
Server
6
7
8
5
9

3.ISP Problem
● Routing
– Internal ISP
– Cross ISP
● Capacity of lease line between 2 ISPs
● Traffic monitoring
– 3G/4G users
● Telco routing

4.ISP to DC Problem
Client Internet
1
2
3
4
Server
Kernel
App
Server
6
7
8
5
9

4.ISP to DC Problem
● Routing
– DC to ISP
– Internal DC
● FW
● Network hardware capability
● Cross product routing
– Bandwidth
– FW
– SDN ????

5.Server Problems
Client Internet
1
2
3
4
Server
Kernel
App
Server
6
7
8
5
9

5.Server Problems
● Network card
– Gigabits
– Fiber
– Virtualization support ???
● CPU
● RAM
● GPU

5.Server Problems
● Scale UP vs scale OUT

5.Server Problems
● How to load balancing between nodes
– HA Proxy
– Nginx
– F5

5.Server Problems
● HA Proxy config sample
backend web-backend
balance roundrobin
server web1 web1.yourdomain.com:80 check
server web2 web2.yourdomain.com:80 check
backend blog-backend
balance roundrobin
mode http
server blog1 blog1.yourdomain.com:80 check

5.Server Problems
● HA Proxy config sample
frontend http
bind *:80
mode http
acl url_blog path_beg /blog
use_backend blog-backend if url_blog
default_backend web-backend

6. Kernel Problems
Client Internet
1
2
3
4
Server
Kernel
App
Server
6
7
8
5
9

6. Kernel Problems
● Drivers for HW optimization
● Max fd
● IP forwarder
● Local FW
– Iptables
● Network IO multiplexing support ???
– EPOLL
● https://code.facebook.com/posts/938078729581886/impro
ving-the-linux-kernel-with-upstream-contributions/

7. Application Problems
Client Internet
1
2
3
4
Server
Kernel
App
Server
6
7
8
5
9

● Data structures
– Array
– Hash map
– Linked list
==> how to use ???

● Caching
– Local Cache
● Use Data structure
– External Cache
● Memcache
● Redis
– Caching algorithm
● LRU
● FIFO
● ….

● Data serialize
– Text Protocol
● Json, XML
– Binary
● Thrift, Protobuff …
– Compression
● Snapy, ZIP, GZIP

● Local cache
– Create a hash map
● localCache = new HashMap();
– Serialize object need to be cached
● serializedObj = JSON.encode(obj);
– Compress data
● compressedObj = GZIP.compress(serializedObj);
– Put to hash cache
● localCache.put(key, compressedObj);

– Get from cache
● compressedObj = localCache.get(key);
– Decompress data
● serializedObj = GZIP.decompress(compressedObj);
– Deserialize
● obj = JSON.decode(serializedObj);

● Caching algorithm
– Memory is limit
– What to do when memory is full
– FiFO ( First In First Out)
● First item inserted will be removed first

– LRU (Least recent used)
http://www.topjavatutorial.com/wp-content/uploads/2016/04/LRU-Cache.png

● How to refresh cache
– Expires
– ????

8. Application to kernel problems
Client Internet
1
2
3
4
Server
Kernel
App
Server
6
7
8
5
9

8. Application to kernel problems
● Memory copy overhead
– Share mem
– Zero copy buffer
● IO multiplexing
– Blocking
● Process base
● Thread base
– Nonblocking
● EPOLL
● KQUEUE
● Use libevent

9.Cross Server Problems
Client Internet
1
2
3
4
Server
Kernel
App
Server
6
7
8
5
9

● Cross platform RPC
– Thrift
– GRPC
– Memcache protocol

● External Cache server
– Memcached
● Memory only
● Slab memory management
● Use libevent for scalable sockets
● Key/Value only
– Twemcache (twitter memcached)
● Heavy
● https://github.com/twitter/twemcache/wiki/Random-
Eviciton-vs-Slab-Automove

Memcached Slabs
(http://charlee.li/memcached-002.html)

● Redis
– Memory and disk
– Simple data structure support
● String, hash, sets, list, sorted sets
– Pub/Sub
– Lua scripts
– Support memcached protocol
– Cluster support

● Redis data structures
https://image.slidesharecdn.com/kickingasswithredis-
120618095415-phpapp02/95/kicking-ass-with-redis-3-728.jpg

Thank you
● Q&A
● We are hiring!!!!
● thanhcnn@vng.com.vn

Cache hcm-topdev

More Related Content

What's hot (14)

Similar to Cache hcm-topdev (20)

Recently uploaded (20)

Cache hcm-topdev