vchub

    _gravity.push({type : 'recommendation',
        callback: callback_fn,
        numberLimit: 4,
        scenarioId: "CATEGORY_PAGE",
        currentItemId: "xxx",
        itemOnPage: [],                  // [] of itemIds already displayed on the page
        resultNames: ["itemId"],

        // фильтр по категории

vchub

// Item page recommendation request and rendering

_gravity.push({type : 'recommendation',
    callback: callback_fn,
    numberLimit: 6,
    scenarioId: "ITEM_PAGE",
    currentItemId: "1111",           // change to item_id in feed
    itemOnPage: [],                  // [] of itemIds already displayed on the page
    resultNames: ["itemId"]          // item attributes present in Item Catalog (feed)

vchub

// function creating a Produc block from data
gravRecoMainYmal = function(data){ console.log(data); }

// reco request
_gravity.push({type : 'recommendation',
    callback: gravRecoMainYmal,
    groupId: "mainpage",
    groupSeq: 1,
    groupSize: 1,
    numberLimit: 16,

vchub

// head>
// ...
<script type="text/javascript">
    /* A/B splitting - Returns either "A" or "B". */
    function getABsplit() {
    var cookieDomain = ".your_domain.ru";
    var cookieName = "gr_split_GLOBAL";
    var cookieExpire = +new Date()+1000*60 * 60 * 24 * 365;

    // get cookie

vchub

Latency numbers every programmer should know

L1 cache reference ......................... 0.5 ns
Branch mispredict ............................ 5 ns
L2 cache reference ........................... 7 ns
Mutex lock/unlock ........................... 25 ns
Main memory reference ...................... 100 ns             
Compress 1K bytes with Zippy ............. 3,000 ns  =   3 µs
Send 2K bytes over 1 Gbps network ....... 20,000 ns  =  20 µs
SSD random read ........................ 150,000 ns  = 150 µs

Read 1 MB sequentially from memory ..... 250,000 ns = 250 µs