what is most optimal way to store an object in redis?

Question

I have a class, which is modeled like this, all member variables are comprising of strings and integers.

> class XYZ extends CFormModel
    {
    //Values required for rendering the Dashboard
    public $username;
    public $analysis_type;
    public $trace_selection;
    public $filter_phantoms;
    public $trace_oui_map;
    public $frame_min;
    public $frame_max;
    public $time_end;
    public $frame_range;
    public $time_range;
    //Other Values
    private $RETURNURL;
    private $PARAMS;
    private $connection;        // connection to db client
    private $database;          // handle to database
    private $col_trace_info;    // handle to trace_info collection
    private $col_csv;           // handle to csv collection
    ...
    ...

I want to store this object of this class in redis cache for performance improvements. Solutions i have stumbled upon to is to use hashmaps..

Yii::app()->cache()->executeCommand("HSET", array("KEY"=>$hashMap, "FIELD"=>$key, "VALUE"=>$object));

My question is, is there a better way to store is object in memory, by using any other data structure or serialize it before storing, or something like that??

Answer 1

Hash Sets are not needed (nor preferred), if you need the complete object or record at retrieval in most of your scenario's. A Hash Set is like a mini-redis database inside Redis. Each key has overhead, and each member of a Hash Set has overhead.

I recommend this approach:

1. Serialize your data as messagepack.
2. Use a Hash Set, but put a complete record in each member of that Hash Set. Only reason for using a Hash Set: This helps keeping things organized. Simple get/set would work as well.
3. If you want an numeric index 'almost' for free, use a Sorted Set instead of a Hash Set. You can use the score as an index. 2.8.9+: Raw alphabetical index also supported: Put everything under score 0 , prefix your msgpack data with an alphabetical identifier/searchstring (plus a delimiter, \t is normally a good one) and use the new function ZRANGEBYLEX.
4. Pipeline your data
5. When doing bulk transfers, wrap the data again in a messagepack container, 1000 records a piece (indication), and let a server-side Lua script do the work for you.

See also here and here

Hope this helps, TW