Copyright © kx.com
Abridged Kdb+tick Manual

1 Summary

Kdb+tick captures, publishes and analyzes millions of streaming ticks as well as the accumulating terabytes of historical data. The realtime and historical databases are in kdb+. Realtime analytic/alert clients can be written in java, .net, c or q. Kdb+tick includes some example clients. see below

2 Architecture

feed>tick>rdb>hdb(historical db) >clients(java,.net,c,q)

Each tickerplant and rdb(realtime db) can handle 100,000 records per second -- more than enough to deal with all trades and quotes, level2 quotes or options. The tickerplant, rdb and hdb(historical) are all 24/7. The latency between feed and rdb is less than one millisecond. Real-time analytic/alert clients can be written in java, c or q. The rdb resets the hdb once a day. See http://kx.com/q/d/taq.htm for a hdb example: nyse trade and quote

3 Hardware

o/s: solaris, linux, windows (32bit or 64bit) cpu: 4 (feed,tick,rdb,hdb,..) ram: 4*daily e.g. 8GB for all US trades and quotes dsk: 2*daily*days(U320 or SAN). 10000rpm+ scsi drives.

The kdb+ storage factor is about 1. Get 2 times as much disk for raid, staging and scratch space. In production (staying less than 50% cpu) the user should have 4 cpus(feed,tick,rdb,hdb) per 4GB of intraday data(with peak 50000 records per second). Backup and development can run with half. The rdb and hdb should be 64bit cpu's.

4 Data

All US equities per day(2004):

trades 200MB quotes 2GB level2 4GB options 6GB

5 Install

Install kdb+. Unzip tick.zip in q/

6 Run

A tickerplant system usually has the tickerplant, realtime db, historical db, one or more feeds and several clients, e.g.

>q tick.q sym DST -p 5010 / load schema tick/sym.q and sets log `:DST/symYYYY.MM.DD >q tick/r.q :5010 -p 5011 / rdb (realtime db gets everything) >q DST/sym -p 5012 / hdb (historical db gets daily snapshot) >q tick/c.q last :5010 / sample last client >q tick/c.q vwap :5010 / sample vwap client >q tick/ssl.q sym :5010 / triarch ssl feed using tick/sym.txt feed (java, .net, c or q) send (".u.upd";table;records)'s to tick. client (java, .net, c or q) subscribe: e.g. .u.sub[`trade`quote;`MSFT.O`IBM.N]

All programs run 24/7. The logs are updated immediately. The clients are updated on a timer loop.

All messages are lists of records -- for higher throughput. The schemas must be ([]time;sym;..) .

The feeds must call (".u.upd";`table;(syms;..)) messages, i.e. time is set by the tickerplant.

The historical database port should be 1+realtime port -- e.g. 5012 -- so the tickerplant can send the reset message.

We provide triarch/ssl and bloomberg feed handlers. The handlers can be on any machine. They can parse about 100,000 records per second -- i.e. more than the feeds can send.

7 Options

>q tick.q SRC DST [-p 5010] [-t 1000] [-o hours] SRC default: sym (tick/sym.q) DST default: none (no log. no rdb.) -p port default: 5010 -t timer milliseconds default: 1000 -o gmt offset hours default: localtime

For testing and replay(http://kx.com/q/tow) don't provide a DST, e.g.

>q tick.q sym

8 Client

Subscribe with:

h:hopen`:host:port h".u.sub[`trade;`MSFT.O`IBM.N]" / subscribe upd:{[t;x]vwap+:select size wsum price,sum size by sym from x} / incremental vwap

The incoming messages are ("upd";`table;table) i.e. in general many records at once.

upd:{[t;x].[t;();,;x]} / all upd:{[t;x].[t;();,;select by sym from x} / last upd:{[t;x].[t;();,'';select time,price,size by sym from x} / nest

In java and c#: (using http://kx.com/q/c/c.jar or http://kx.com/q/c/c.cs)

k.c(".u.sub[`trade;`MSFT.O`IBM.N]"); while(true){Object x=k.c();Console.WriteLine(at(x,1));alerts..} // print incoming table name

In c:

k(c,".u.sub[`trade;`MSFT.O`IBM.N]",0); while(1){K x=k(c,0);printf("%s\n",KK(x)[1]->s);alerts..}

Watch out: a bad client(doesn't keep up) will cause the tickerplant to buffer up all the messages.

9 Maintenance

Possibly reset feed subscription list every day.

10 Feed

triarch/ssl subscribers

l32/ssl.so s32/ssl.so w32/ssl.dll

these have to run 32bit because triarch is 32bit.

the tickerplant can be anywhere/anything.

11 Examples

options and underlying: two tick's. one client subscribes to both.

rolling vwap, e.g. every 10 seconds

sub[`trade;..] upd:insert .z.ts:{push r:select size wavg price by sym from trade;trade::();r} \t 10000 / all trades with then current quote upd:{[t;x]$[t~`trade;trade,:x lj quote; quote,:select last bid,last ask by sym from x]}

We can also keep track of nbbo (or the entire book) if there are multiple market makers,

12 Comments

Minimal Ticker Plant Memory usage

The kdb+ TP holds only one second's worth of data in memory. It instantly logs incoming data.

24/7(365)

Kdb+ has built-in daily rollover mechanisms to eliminate downtime. All processes can run forever.

Scalability and Resilience

Real Time subscribers can subscribe at any time during the day without overloading or delaying the plant. This is because the rdb loads the day's tick data from disk and then continues to receive updates via tcp/ip.

Efficient Subscription

Kdb+ plants allow table subscription by symbol - i.e. the plant sends only symbol data that the client has requested. This allows slower (desktop java/.net/excel) processes to be connected without the client thrashing to filter unwanted data.

Increased Memory Space

Processes can hold more data in memory - allows process types (depth/stock/option) for a region to be combined into a single kdb+ process, reducing duplication of data across databases, simplifies query writing, and eases configuration management/support.

Simpler Query Language

The new unified query language, Q, is much simpler and more flexible to write queries.

Competitive Advantage

The old kdb is no longer the best product for processing tick data. Kdb+ is.