Music for December

EBM, industrial, and some other random stuff:
http://www.pimpworks.org/~killgreedy/

some trance and EBM:
http://fawx.net/jag/music/

mostly rock and pop, but there is a motherload here, possibly 40-50 gb:

http://duesti209.dyndns.org/root/Musik/

Unix: find largest files / folder to free up space

Unix boxes like to fill up with log files, and when they get really full, stuff starts to break. These commands will tell you where the big log files sit so you can delete them or gzip them.

first, in root run
df -k
/dev/md/dsk/d3 4129290 4020939 67059 99% /var

then go to /var and find what it taking up all the space:
du -sk * | sort -m | head
2855134 mail
..
193102 tmp

so mail is taking up space, now lets look for files bigger then 100MB:
find . -size +100000000c -ls
22615 483984 -rw-r--r-- 1 root other 495339455 Dec 14 15:09 ./mail/access_log
113593 209784 -rw-r--r-- 1 root other 214696853 Dec 14 15:08 ./mail/servletd.log
208492 354768 -rw-rw-rw- 1 admin mail 363091751 Dec 14 14:29 ./mail/admin

now you can see what is steal your megabytes.

the most useful program in the world

clear&&perl -e'$|=1;@l=qw{| / -  \\};while(){print 
qq{$l[$_++%@l]\x0d};select($z,$z,$z,.2*(rand(2)**2))}'

i can think of like 9 uses for this already!

Websphere: starting up and shutting down

I have a websphere 6 clustered enviornment that i sometimes need to start up and shut down without using the web console.

there are 2 boxes in the cluster, one of them has the deployment manager on it.

each box runs 2 JVMs, which are called are called App1 and App1.1

The box that has the deployment manager needs to start/stop that, while the other does not.

FOR SHUTDOWN:
[WAS_HOME]/profiles/AppSrv01/bin/stopServer.sh App1 -username [user] -password [pass]
[WAS_HOME]/profiles/AppSrv01/bin/stopServer.sh App1.1 -username [user] -password [pass]
[WAS_HOME]/profiles/AppSrv01/bin/stopNode.sh -username [user] -password [pass]
[WAS_HOME]/profiles/Dmgr01/bin/stopManager.sh -username [user] -password [pass]

FOR STARTUP:
[WAS_HOME]/profiles/Dmgr01/bin/startManager.sh -username [user] -password [pass]
[WAS_HOME]/profiles/AppSrv01/bin/startNode.sh -username [user] -password [pass]
[WAS_HOME]/profiles/AppSrv01/bin/startServer.sh App1 -username [user] -password [pass]
[WAS_HOME]/profiles/AppSrv01/bin/startServer.sh App1.1 -username [user] -password [pass]

regex to split a document into words

Say you wanted to split a document into words, but works like are'nt shouldnt be split on the ' and numbers like 10,004,333 should remain intact, but other punctuation should be removed from the resulting word array.

A good way to do this is using Scanner's findWithinHorizon and a regular expression. This way you dont need to read the entire document into memory before processing it.

<br />Pattern p = Pattern.compile("[A-Za-z]+(?:['-][A-Za-z]+)?|\\d+(?:[,.]\\d+)?");<br />Scanner sc = new Scanner(new File("/path/to/the/file.txt"));<br />String word = null;<br />while ((word = sc.findWithinHorizon(p, 0)) != null)<br />{<br /> // etc.<br />}<br />

Teamsite DCT design considerations

I dont claim to be an expert on Teamsite, but i have put much blood sweat and tears into it. The following is my understanding of how teamsite tracks database changes, and what that means for anyone who designs datacapture templates and uses OpenDeploy.

The IWDELTRACKER tables uses the following info to track records: path of the xml, all its primary keys as defined in the dd files, and all its foreign keys. This works really well if you have 1 primary key, which is paired up with many foreign keys, but not so well if you have many primary keys, which are paired up with many(or one) foreign keys. This is the reason why one of my DCTs is flawed. In this DCT you make a resource, and assign it to many areas, so the primary key in that DCT comes from a replicant, and the foreign key comes from the main body. The problem we are facing with resource DCT right now is that if the user maps a resource to many areas, and then they delete some areas from the DCT, the changes are not deployed to the database.

Rules of thumb are:

1. Only create top-down relationships
2. NEVER use a replicant for a UID
3. Always test for relationship deletions.

Oracle: convert nclob to nvarchar2 (part 2)

I needed to convert a column in a database from NCLOB to NVARCHAR2(2000) which is the max you can store in NVARCHAR2. The problem was that some columns in the table where larger then 2000 chars. To solve this i needed to use the oracle length function to select only rows who's lenth was less then 2000. In this example sql, the table that has the NCLOB is called THETABLE, and the column that needs to become NVARCHAR2 is called THECOLUMN.

<br />CREATE TABLE THETABLE_TEMP as select * from THETABLE;<br />alter table THETABLE drop COLUMN THECOLUMN;<br />alter table THETABLE add (THECOLUMN NVARCHAR2(2000));<br />UPDATE THETABLE p SET p.THECOLUMN = <br />(SELECT t.THECOLUMN FROM THETABLE_TEMP t <br />WHERE t.PRIMEKEY = p.PRIMEKEY <br />and dbms_lob.getlength(t.THECOLUMN) <= 2000) <br />

dbms_lob.getlength(column) is the key to success here

IWDatacapture.callServer call fails / caveat

problem:

when i build teamsite DCTs i always find a new and wonderful way to break something.

Today i was building a DCT that used IWDatacapture.callServer to call a cgi script that would get some stuff from the database and then out put it into a hidden frame and do a javascript callback to the parent window.

everything was going well until i made the mistake of making 2 calls to different IWDatacapture.callServer cgi scripts one right after the other. one of them would always fail.

solution:
The problem stems from the fact that CGI scripts that output html make use of a single blank.html file to write out their contents. If you call 2 of them "almost at the same time" one of them will overwrite the other's blank.html file and cause it to fail. The only reasonable solution is to combine both CGIs into one file and let it write to one blank.html file, you can also try to make sure that CGIs dont get called at the same time, but that would be difficult to control.

So it seems that its probably a reasonable requirement to only allow ONE IWDatacapture.callServer call per DCR, otherwise things might break. How sad.

Java: Understanding Weak References

The other day i was reading programming at reddit and stumbled on this article:
Understanding Weak References which was a good read but i still had some questions, so i turned to Java Developer Forums for help. I didnt get flamed! (much). What i got was a very good response from a user named kdgregory which is note-to-dogself worthy.

My questions are in blue boxes:

If weak references are great at stopping leaks, why not use them all the time?

They're great at stopping leaks in the situation where you're attaching data to an object that (should) have a limited lifetime. If you used a regular map (most likely an IdentityHashMap), you'd be creating a strong reference to the object via the map, so it would never be collected, even when there are no other references to it (I call this a leak, other people don't).

For example, ThreadLocal uses weak references, because they'll be cleared when the thread ends.

ObjectOutputStream should use weak references (and a changed protocol) so that it can be used in long-running conversations without constantly calling reset(). But it doesn't.

"WeakHashMap works exactly like HashMap, except that the keys (not the values!) are referred to using weak references."

• does this imply that hashmap stores values in weak refs, if so, why?

• should i use WeakHashMap for tasks where i will have another reference to objects i put into the map. ie i dont put my only ref into this map?

No, HashMap doesn't use weak references for either key or value. The author's wording (and for that matter, the JDK JavaDoc wording) is a little misleading.

One typical use for weak references is in a canonicalizing map to reduce memory consumption with duplicated data. With such a map, you would store an object as both key and value, and retrieve the canonical value when presented with an arbitrary key -- think String.intern(). However, you can't use WeakHashMap to do this without wrapping the value in a weak reference also.

When do i not use weak references ?

Most of the time. Any reference object means that you have to access your original object in two steps (have to call get() on the reference) rather than just one. And normally, you'd know the lifetime of your objects.

music for november

Using the google mp3 search i find some good stuff, im going to put all the november music into this post.

this place has a player built in, very nice:
http://media.soundfixrecords.com/player/xspf_player.swf

lots of full albums here - seems like dance / dnb:
http://danav.org/audio/

parse xml with JDOM and Xpath

every now and again its good to have your config in an xml file, but i am usually to lazy to remember to how to do it properly and just use java.util.Properties. Well no more of that!

This is a short self contained code sample on how to parse some xml using jdom and jaxen

you will need:
jdom lib
jaxen lib (which may be old now)

<br /> public void example() throws JDOMException, IOException {<br /> // import org.jdom.Document;<br /> // import org.jdom.Element;<br /> // import org.jdom.JDOMException;<br /> // import org.jdom.input.SAXBuilder;<br /> // import org.jdom.xpath.XPath;<br /> String fn = "/path/to/some.xml";<br /> FileInputStream in = new FileInputStream(fn);<br /> SAXBuilder builder = new SAXBuilder();<br /> Document doc = builder.build(in);<br /> in.close();<br /> XPath xpath = XPath.newInstance("//some/xpath[1]/expression");<br /> List list = xpath.selectNodes(doc);<br /> for (Iterator iter = list.iterator(); iter.hasNext();) {<br /> Element elem = (Element) iter.next();<br /> <br /> String name = elem.getAttributeValue("name");<br /> String childText = elem.getChild("child").getTextTrim();<br /> String text = elem.getTextTrim();<br /> }<br /> }<br />

wait in windows bat script - good way

i recently wrote about using ping to pause for a number of seconds in a batch script. It was brought to my attention that you can use /wait to actually wait for a process to complete like so:

start /wait /i "unimportant title put whatever here" "C:\path\to\some\executable.exe"

or if you have an msi installer you can do this:

msiexec /i "C:\path\to\msiinstaller.msi" /qr

extract links using htmlparser

i have come to realize that even though i love to do everything in regex, extracting links with regex is not really the best idea.

the best idea is to use htmlparser to extract the links.

This code sniplet will extract links from a page body, and given the link where the body was found it will resolve the relative links. This is tailored to be used by a crawler.

<br />public static Collection<String> retrieveLinks(String url, byte[] body, String charSet) {<br /><br /> Collection<String> result = new ArrayList<String>();<br /> <br /> URI uriLink;<br /> try {<br /> uriLink = new URI(url);//url of the body<br /> String st = new String(body, charSet);<br /> Parser parser = new Parser();<br /> parser.setInputHTML(st);<br /> NodeList list = parser.extractAllNodesThatMatch(new NodeClassFilter (LinkTag.class));<br /> for (int i = 0; i < list.size (); i++){<br /> LinkTag extracted = (LinkTag)list.elementAt(i);<br /> <br /> if(!extracted.isHTTPLikeLink()) continue; //ignore mailto / javascript and other weird protocol links<br /> <br /> <br /> String extractedLink = extracted.extractLink().replaceAll("&", "&");//we need to unescape these<br /> <br /> extractedLink = extractedLink.replaceAll(" ","%20");//URI class doesnt like spaces in URLs, but content creators dont care.. :P<br /> extractedLink = extractedLink.trim();//URI will barf on a link that look like "foo.com "<br /> if(extractedLink.length() == 0) continue; // i am betting that a link that looks like "" is user error. with our url scheme, it most certainly is.. <br /> if(extractedLink.startsWith("#")) continue; //skip all anchors, they are useless to a crawler<br /> if(extractedLink.matches("(?i)^javascript:.*"))continue; //HTMLParser thinks anything but lower case 'javascript:' is a non-js link<br /> <br /> URI uriRelative = new URI(extractedLink);<br /> //System.out.println("i:"+i);<br /> URI resolved = uriLink.resolve(uriRelative);<br /> //linkfilter will return true if crawling from <br /> //url --> resolvedUrl<br /> //is allowed by some rules<br /> String link = resolved.toString();<br /> //here we should check if the link is acceptable.<br /> result.add(link);<br /> <br /> }<br /> }<br /> } catch (URISyntaxException e) {<br /> // TODO: this is a bad link, log this!<br /> log.info("Bad Link Syntax on page:["+url+"] BAD LINK:"+e.getMessage());<br /> } catch (UnsupportedEncodingException e) {<br /> // TODO Auto-generated catch block<br /> e.printStackTrace();<br /> } catch (ParserException e) {<br /> // TODO Auto-generated catch block<br /> e.printStackTrace();<br /> } <br /> <br /> return result;<br /> }<br />

wait or pause in windows batch script

problem:
i am told that windows .bat files do not have a sleep or wait command.
this is pretty sucky for when you want to wait or sleep, isnt it?

solution:
do this terrible hack
ping 1.0.0.0 -n 1 -w 5000 >NUL

that will block for 5 seconds. yey!

also, if you need to wait for a process to finish, i blogged about that here

also, if you have the ability to install something on the box where you will run your script, you should get the Windows Server 2003 Resource Kit tools from Microsoft: which works with XP. This gives you a real sleep command! (Thanks to Tricky for pointing this out in the comments)

extract links from a webpage

this is useful if you decide to make a web crawler, and dont want to bother with an html parser. You have to read the body of the page into a string, and then use this regex to extract all the links.

supported link types: <img src=...<a href=...
<br /><br />String body = "..."; //body of the page<br />Matcher m = Pattern.compile("(?im)(?:(?:(?:href)|(?:src))[ ]*?=[ ]*?[\"'])(((?:http|https)(?::\\/{2}[\\w]+)(?:[\\/|\\.]?)(?:[^\\s\"]*))|((?:\\/{0,1}[\\w\\.]+)+))[\"']").matcher(body);<br />while(m.find()){<br />String absolute = m.group(2);<br />String relative = m.group(3);<br />}<br />

an absolute url is in the form of "http://something.com/blah"
a relative url is in the form of "/something/path.blee"

now you can figure out what to do with these...

SQL: change column datatype

in this note to self, i need have a table where a column (COL2) is an NVARCHAR, and it need to become an NCLOB:

CREATE table TABLENAME_TEMP as select * from TABLENAME;
ALTER table TABLENAME drop COLUMN COL2;
DELETE from TABLENAME;
ALTER table TABLENAME add (COL2 NCLOB NOT NULL);
-- at this point the columns may not line up, so specify order...
INSERT into TABLENAME TN (TN.COL1, TN.COL3, TN.COL2) select * from TABLENAME_TEMP;
COMMIT;
DROP table TABLENAME_TEMP;

now the table TABLENAME has a column which is an NCLOB, yey!s

Remove HTML tags regex

when using an HTML parser is too much work, you may want to use a small regex to remove all the html tags

this is java:
<br />String output = input.replaceAll("</?\\w++[^>]*+>", "");<br />

Teamsite: default OpenDeploy URL

http://TS-server:8081/iw/opendeploy/login

Opendeploy deployment fails with "REQUEST_DENIED"

Problem:
I am trying to manually kick off a teamsite deployment with opendeploy 6.1, and i get this error:

Executing(ant): /app/OpenDeployNG/bin/iwodcmd start ddconfig.xml -k iwdd=deployment1

Locating OpenDeploy service.
Got OpenDeploy service
>>>>>-- Start deployment ddconfig.
iwodstart running in default synchronous mode.
Need to wait for deployment to complete.
***ERROR - Starting deployment.
Caught exception. Details: REQUEST_DENIED

Solution:
in [OD_HOME]\bin run the following command as root:
./iwodauthorize -r add od-admin [user you tried to deploy as]
so in my case:
./iwodauthorize -r add od-admin ant

then list all the users who can run deployments, just to check if it worked:
./iwodauthorize -r list od-admin

Good place for EBM and Industrial?

a bunch of different stuff:
http://www.vysniukas.com/download/-%20music/

http://www.stormwish.com/music/?N=A

a bunch of goth stuff within

http://www.gwydion.net/~helen/

some music which is good, and also some which is not so good

this has a ton of stuff:
http://maelwys.psyche7.net/

check out the music folder