iboxdb / ftserver

Lightweight Full Text Search Server for Java

Setup

Use NetBeans with [JDK8+] to build or download fts.zip(WAR) from WAR Folder
Deploy to tomcat/jetty


for OpenJDK, to use OpenJDK 11+ for better GC

Dependencies

iBoxDB

Semantic-UI

Jsoup

The Results Order

The results order based on the id() number in class PageText, descending order.

Page has many PageTexts.

the Page.GetRandomContent() method is used to keep the Search-Page-Content always changing, doesn't affect the real PageText order.

if you have many pages(>100,000), use the ID number to control the order instead of loading all pages to memory. Or you can load top 100-1000 pages to memory then re-order it by favor.

Search Format

[Word1 Word2 Word3] => text has Word1 and Word2 and Word3

["Word1 Word2 Word3"] => text has "Word1 Word2 Word3" as a whole

Search [https http] => get almost all pages

Search Method

search (... String keywords, long startId, long count)

startId => which ID(the id when you created PageText) to start, use (startId=Long.MaxValue) to read from the top, descending order

count => records to read, important parameter, the search speed depends on this parameter, not how big the data is.

Next Page

set the startId as the last id from the results of search minus one

startId = search( "keywords", startId, count);
nextpage_startId = startId - 1 // this 'minus one' has done inside search()
...
//read next page
search("keywords", nextpage_startId, count)

mostly, the nextpage_startId is posted from client browser when user reached the end of webpage, and set the default nextpage_startId=Long.MaxValue, in javascript the big number have to write as String ("'" + nextpage_startId + "'")

The Page-Text and the Text-Index -Process flow

When Insert

1.insert page --> 2.insert index

IndexAPI.addPage(p);
IndexAPI.addPageIndex(url);

When Delete

1.delete index --> 2.delete page

IndexAPI.removePage(url);

Add Custom information to Page

input format:

line1 : Title ...
line2 : Text Text ...

Private Server

Open

public Page Html.get(String url);

Set your private WebSite text

Page page = new Page();
page.url = url;
page.title = title;
page.text = replace(doc.body().text());
page... = ...
return page;

Memory

//Bigger, faster, more memories.
//Smaller, less memory.
int PageText.max_text_length ;

How to set big cache

//-Xmx8G
DatabaseConfig dbcfg = db.getConfig(); 
dbcfg.CacheLength = dbcfg.mb(2048);
//Or
dbcfg.CacheLength = 2048L * 1024L * 1024L;

//Wrong, overflow
//dbcfg.CacheLength = 2048 * 1024 * 1024;

Turn off SWAP

Turn off virtual memory for 8G+ RAM Machine
use DatabaseConfig.CacheLength and PageText.max_text_length to Control Memory

Linux:
 # free -h
 # sudo swapoff -a
 # free -h 

Windows:
System Properties(Win+Pause) - Advanced system settings - Advanced
- Performance Settings - Advanced - Virtual Memory Change -
uncheck Automatically manage paging file - select No paging file - 
click Set - OK restart

More

C# ASP.NET Core Version