I came across what looks to be a handy method to dump a Java object to a string (and no, I don’t mean toString()). I guess I’m spoiled by <cfdump> in ColdFusion and have got used having a visual indicator as to what an object actually looks like when trying to debug something. I haven’t yet given this code a try so I can’t speak for how well it works, but I should have a use for it soon.
I went ahead and setup a server based IRC client for anyone who can’t get on Sean’s IRC server because of firewall restrictions. As long as it doesn’t get abused, eat-up my server and bandwidth resources, or isn’t replaced by something better, I’ll leave it up. Enjoy. 
7/26/05 Update:
Unfortunately the IRC server does not like multiple logins from one host, and as such my IP has been K-lined for a week and a half, so I can’t even login from home now. I’ve taken the client down… sorry.
I just came across an older post from Steven Brownlee about how to run multiple instances of ColdFusion all deployed from the same ColdFusion Application instance. This configuration looks to be extremely handy, especially if you find yourself having to add/remove/edit datasources fairly often.
I’m sure I’m not the only one who has been tempted by the Harmonics laminate wood flooring at CostCo, right? My first dog did quite a bit of damage to my carpet, and the current one has had a couple of accidents (for having her for 1.5 years now, she’s honestly done really well), so in general the cheap crappy carpet in my place is pretty much shot. I’ve always liked wood flooring, and laminate flooring is supposed to be better with pets as far as not getting scratched-up is concerned. While doing research about it, I found a whole ton of information about the stuff you see at CostCo.
I’d say my takeaway from my research is that if you pick it up while it’s on sale, it ends up being only around $1.50 s/f INCLUDING padding, and overall it’s a pretty decent system. Sounds like it’s fairly easy to do yourself as well as long as you have someone there to help you cut pieces, etc, so you don’t have to get up and down all the time.
I came across the Django project yesterday (which was also released yesterday) which looks to be a very cool framework for developing Python web apps. It’s certainly not the “same” as Ruby On Rails by any means (for instance, to me it looks like you actually design your database in code rather than feeding your app a database to auto discover), but offers what looks to be a competitive Python alternative to it. It also makes me happy that it’s preferred database platform is Postgres as it’s something I’ve been meaning to check-out for quite some time.
Though Python doesn’t quite have the buzz that Ruby does at the moment, its a soild, stable, robust language which was originally started in 1989, and is even used by quite an impressive list of companies such as Google.
On Sunday, March 6th of 2005 I was messing around on my workstation retagging some Mp3’s so I could add them into my iPod playlists when I got a GMail notification of a new comment on my blog. I went to check it out and it was fairly basic comment “prepare to be slashdotted. I went to check-out Slashdot and didn’t see anything there, so I assumed it was likely just a spam comment. It wasn’t long after that when a link to an entry I’d wrote a couple of months previous appeared at the top of their front page.
I was actually quite shocked—being linked to from Slashdot is a very big deal in the geek community. For those not familiar with Slashdot, the best comparison I can make is if you were an amateur author and had your work published in Newsweek or something like that. Slashdot does not have nearly the readership of Newsweek, but it’s certainly one of the most trafficked international geek news sites that I know of offhand– I’m a regular reader myself.
Once I knew for sure I was getting Slashdotted, I actually decided to get-up from the computer and go do something else while I thought about how I could prepare for a load like that rather than freaking out and breaking things. My server at the time was a temporary server built out of spare parts (I host my site at home) which was over 6 years old, so I had no idea what I’d be able to do with it. After remembering articles several years ago about something to the effect of “A Pentium 90 can easily put out enough bandwidth to saturate a T1�?, I kept that in mind and started to think of ways to eliminate bottlenecks. I eventually came back, saw that my server was non-responsive via HTTP. I then blocked port 80 at the firewall, and went to work.
I was not a bit surprised the server was non-responsive; my site at the time was running on a Celeron 466 with 192 MB of RAM. I also of course used Apache HTTPD Server, as well as PHP5 and MySQL to power my Wordpress blog in which the entry was in that was being linked to.
My first course of action was to figure-out how to make the page static so that it wouldn’t have to hit MySQL each time someone requested that page. I assumed there was probably a Wordpress plug-in to do this with, so I googled for one and found one which Matt Mullenweg himself was using, Staticize Reloaded. (Note: I’ve since switched to an upgraded version of the same plugin.) This was a major help, but not quite enough given that I hadn’t really touched this particular FreeBSD install much as it was temporary until my new server came in.
My second major course of action was to change the settings on Apache to keep it from dying. It’s been quite some time since all of this happened so I don’t remember the exact settings I used, but basically I upped the number of min and max servers, set a server timeout of 15 seconds, and made sure new server processes were started every 500 requests or so to keep runaway processes from killing the server.
One last thing I did was kill all unnecessary processes such as SMTP (I knew my mail would queue on external SMTP servers trying to reach mine, and I get more spam than legitimate mail anyhow), made sure nothing in cron was intensive, etc. Had bandwidth also been a problem after these changes, I planned on moving my site to the default Wordpress template which did not have any graphics—just XHTML & CSS.
From there I decided to reboot the box just to clean it up and open port 80 back-up again to accept HTTP traffic again. Surprisingly FreeBSD never once crashed the whole time even after the initial Slashdotting before I started blocking traffic.. it was just very bogged down with requests (mostly MySQL was dying). I rebooted it after changing the configuration as a precautionary measure. This was a very stock install of FreeBSD– I didn’t even make a custom kernel for it or anything.
Once I put the box back in, it took a bit more Apache tweaking to get it perfect, but eventually my spare parts Celeron 466 was handling a Slashdotting at only 30% CPU utilization! Here is an example of the number of connections it was getting (which is crazy for me to see on a personal machine) as the Slashdot effect was winding down:
Active Internet connections Proto Recv-Q Send-Q Local Address Foreign Address (state) tcp4 0 791 grimmace.http puddle189.drizzl.3055 ESTABLISHED tcp4 0 33580 grimmace.http c-67-166-235-247.4364 ESTABLISHED tcp4 0 0 grimmace.http 213.58.2.244.1227 ESTABLISHED tcp4 0 32120 grimmace.http puddle189.drizzl.3054 ESTABLISHED tcp4 0 26018 grimmace.http c-67-166-235-247.4363 ESTABLISHED tcp4 0 0 grimmace.http planetlab2.georg.55584 TIME_WAIT tcp4 0 0 grimmace.http c-67-170-48-141..61898 ESTABLISHED tcp4 0 0 grimmace.http tide505.microsof.39548 ESTABLISHED tcp4 0 0 grimmace.http tide532.microsof.54754 ESTABLISHED tcp4 0 0 grimmace.http unassigned.purec.1361 ESTABLISHED tcp4 0 0 grimmace.http c-67-170-48-141..61897 ESTABLISHED tcp4 0 0 grimmace.http tide508.microsof.30208 ESTABLISHED tcp4 0 0 grimmace.http tide70.microsoft.53537 ESTABLISHED tcp4 0 0 grimmace.http c-24-19-42-108.c.4436 ESTABLISHED tcp4 0 0 grimmace.http tide85.microsoft.40545 ESTABLISHED tcp4 0 0 grimmace.http S01060050baa51fa.33235 ESTABLISHED tcp4 0 0 grimmace.http c-24-19-42-108.c.4434 ESTABLISHED tcp4 0 0 grimmace.http S01060050baa51fa.33234 ESTABLISHED tcp4 0 0 grimmace.http tide85.microsoft.40500 ESTABLISHED tcp4 0 0 grimmace.http tide531.microsof.36377 FIN_WAIT_2 tcp4 0 0 grimmace.http tide517.microsof.12997 FIN_WAIT_2 tcp4 0 0 grimmace.http tide518.microsof.18692 FIN_WAIT_2 tcp4 0 0 grimmace.http tide510.microsof.52133 ESTABLISHED tcp4 0 0 grimmace.http c-67-182-8-198.c.60914 FIN_WAIT_2 tcp4 0 0 grimmace.http 68-113-20-232.wa.37925 ESTABLISHED tcp4 0 0 grimmace.http c-67-182-8-198.c.60913 FIN_WAIT_2 tcp4 0 0 grimmace.http 68-113-20-232.wa.37924 ESTABLISHED tcp4 0 0 grimmace.http msnbot.msn.com.37805 TIME_WAIT tcp4 0 12427 grimmace.http dial-148-240-184.3124 ESTABLISHED tcp4 0 0 grimmace.http pool-68-163-42-6.4368 TIME_WAIT tcp4 0 0 grimmace.http unassigned.purec.1359 ESTABLISHED tcp4 0 32327 grimmace.http dial-148-240-184.3122 ESTABLISHED tcp4 0 0 grimmace.http relax15.idiap.ch.40978 TIME_WAIT tcp4 0 0 grimmace.http relax15.idiap.ch.40977 TIME_WAIT tcp4 0 0 grimmace.http pool-68-163-42-6.4366 TIME_WAIT tcp4 0 0 grimmace.http relax15.idiap.ch.40975 TIME_WAIT tcp4 0 0 grimmace.http 24.125.148.80.1176 TIME_WAIT tcp4 0 0 grimmace.http 213.58.2.244.1208 TIME_WAIT tcp4 0 0 grimmace.http CPE0050da6ab5da-.3371 TIME_WAIT tcp4 0 0 grimmace.http 24.125.148.80.1175 TIME_WAIT tcp4 0 0 grimmace.http adsl-70-240-237-.1266 FIN_WAIT_2 tcp4 0 0 grimmace.http CPE0050da6ab5da-.3370 TIME_WAIT tcp4 0 0 grimmace.http bbox.ne.client2..47283 TIME_WAIT tcp4 0 0 grimmace.http msnbot.msn.com.36671 TIME_WAIT tcp4 0 0 grimmace.http host-148-244-150.46757 TIME_WAIT tcp4 0 0 grimmace.http hannibal.lr-s.tu.50584 TIME_WAIT tcp4 0 0 grimmace.http rdu25-17-055.nc..54974 TIME_WAIT tcp4 0 0 grimmace.http 163.80-202-31.ne.57984 TIME_WAIT tcp4 0 0 grimmace.http bbox.ne.client2..47282 TIME_WAIT tcp4 0 0 grimmace.http rdu25-17-055.nc..54973 TIME_WAIT tcp4 0 0 grimmace.http hannibal.lr-s.tu.50578 TIME_WAIT tcp4 0 0 grimmace.http c-67-174-111-123.3682 TIME_WAIT tcp4 0 0 grimmace.http c-67-174-111-123.3681 TIME_WAIT tcp4 0 0 grimmace.http c-67-174-111-123.3680 TIME_WAIT tcp4 0 0 grimmace.http relax15.idiap.ch.40952 TIME_WAIT tcp4 0 0 grimmace.http relax15.idiap.ch.40953 TIME_WAIT tcp4 0 0 grimmace.http c-67-174-111-123.3679 TIME_WAIT tcp4 0 33304 grimmace.http relax15.idiap.ch.40943 LAST_ACK tcp4 0 0 grimmace.http 163.80-202-31.ne.57983 TIME_WAIT tcp4 0 33304 grimmace.http relax15.idiap.ch.40931 CLOSE_WAIT tcp4 0 0 grimmace.http ool-4570bffb.dyn.54562 TIME_WAIT tcp4 0 0 grimmace.http 208-59-174-198.c.1771 TIME_WAIT tcp4 0 0 grimmace.http xdsl-81-173-248-.3833 TIME_WAIT tcp4 0 0 grimmace.http 24-117-147-243.c.60104 TIME_WAIT tcp4 0 0 grimmace.http pcp658486pcs.cap.29623 TIME_WAIT tcp4 0 0 grimmace.http pcp658486pcs.cap.29622 TIME_WAIT tcp4 0 0 grimmace.http ool-4570bffb.dyn.54558 TIME_WAIT tcp4 0 0 grimmace.http 208-59-174-198.c.1770 TIME_WAIT tcp4 0 0 grimmace.http 24-117-147-243.c.60103 TIME_WAIT tcp4 0 0 grimmace.http xdsl-81-173-248-.3825 TIME_WAIT tcp4 0 0 grimmace.http pool-68-238-49-1.50253 TIME_WAIT tcp4 0 0 grimmace.http pool-68-238-49-1.50252 TIME_WAIT tcp4 0 0 grimmace.http pool-68-238-49-1.50251 TIME_WAIT tcp4 0 0 grimmace.http pool-68-238-49-1.50250 TIME_WAIT tcp4 0 24300 grimmace.http ip160-108.om.apa.14426 CLOSING tcp4 0 30640 grimmace.http ip160-108.om.apa.14403 FIN_WAIT_1 tcp4 0 33304 grimmace.http 209.237.230.104.21469 ESTABLISHED tcp4 0 33580 grimmace.http S010600067b078af.1423 ESTABLISHED tcp4 0 29326 grimmace.http bidwell.textdriv.55107 FIN_WAIT_1 tcp4 0 0 grimmace.http c68.115.108.235..3517 FIN_WAIT_1 tcp4 0 0 grimmace.http c68.115.108.235..3516 FIN_WAIT_1 tcp4 0 0 grimmace.http cust1392.vic01.d.20836 FIN_WAIT_1 tcp4 0 0 grimmace.http node-423a2a62.df.62359 FIN_WAIT_1 tcp4 0 0 grimmace.http cust1392.vic01.d.20835 FIN_WAIT_1 tcp4 0 0 grimmace.http node-423a2a62.df.62358 FIN_WAIT_1 tcp4 0 0 grimmace.http 66.89.66.69.ptr..57168 FIN_WAIT_1 tcp4 0 0 grimmace.http 81.104.95.80.ip..13863 FIN_WAIT_2 tcp4 0 0 grimmace.http 66.89.66.69.ptr..57166 FIN_WAIT_1 tcp4 0 0 grimmace.http 81.104.95.80.ip..13854 FIN_WAIT_1 tcp4 0 0 grimmace.http lata228-05-c136..29431 FIN_WAIT_2 tcp4 0 0 grimmace.http lata228-05-c136..29430 FIN_WAIT_2 tcp4 0 24300 grimmace.http ip160-108.om.apa.14400 CLOSING tcp4 0 0 grimmace.http 207-171-180-101..44370 FIN_WAIT_1 tcp4 0 0 grimmace.http 207-171-180-101..44302 FIN_WAIT_1 tcp4 0 0 grimmace.http lata228-05-c136..29429 FIN_WAIT_2 tcp4 0 0 grimmace.http lata228-05-c136..29428 FIN_WAIT_2 tcp4 0 0 grimmace.http ausisapc102-dmz..22690 FIN_WAIT_2 tcp4 0 0 grimmace.http h000625d8511c.ne.4303 FIN_WAIT_2 tcp4 0 0 grimmace.http 209.237.230.104.28587 FIN_WAIT_2 tcp4 0 0 grimmace.http 66.193.93.3.47306 FIN_WAIT_2 tcp4 0 0 grimmace.http 66.193.93.3.47302 FIN_WAIT_2 tcp4 0 0 grimmace.http adsl-6-96-227.ms.46767 FIN_WAIT_2 tcp4 0 33580 grimmace.http c-24-6-68-25.cli.1107 ESTABLISHED
Unfortunately I’d estimate I was offline for around 2 hours while I fixed the machine, etc, so there is no telling how much traffic I would of seen while my site was the top link on Slashdot, but here are a few graphical examples of what type of traffic I saw once I got the server working (I think it would have been significantly more had it not been on a Sunday afternoon.):
Usually I do around 2-2.5 GB of web traffic per month, but in one day I did over 4 GB! Granted this isn’t impressive compared to a real production environment, but not bad for an old Celeron on a DSL line. I’ve also had one of my entries end up on del.ici.ous/popular which upped my traffic to about 4 GB+ of bandwidth in a month, but it was much more steady rather than one big rush of requests all at once.
I had other stuff to do on Sunday other than sit around on the computer, but I did spend a considerable amount of time responding to comments both on Slashdot as well as my own site. Surprisingly I didn’t get any comments which I was forced to delete. I did however have some other strange experiences which I recently wrote about.
I’d say my main highlights to pass on from this experience are:
All in all it was a very interesting experience, and hopefully it will happen again sometime. The server which was on order at the time is currently serving the site, and should be able to handle much more load without me needing to touch it if it were to happen again, but we’ll see…
Previously I was using a caching plugin for Wordpress that eventually started breaking RSS, so I had to remove it. I’ve added a much updated version of that again to the site, so let me know if you experience any problems!
FWIW, this plugin helped me survive a Slashdotting (which I’m finally writing about.. stay tuned).
Sean Corfield just announced that he’ll be speaking at the Denver CFUG on August 8th. Following his presentations that I attended at CFUNITED last week as well as having a chance to talk to him for a bit there (much less the many things he’s done for the tech world over the years) I highly recommend attending this event if you’re in the Denver area.
Over the past few working days I’ve been making some minor enhancements / bug fixes to a reporting product currently in beta. Said product at a 50,000 foot view basically compiles a report into a massive structure which I then convert to WDDX and store in a database so that it can be transformed easily into different display formats as well as viewed at a later date.
Out of the blue I kept getting low-level errors like this whenever the structure was convered to WDDX from the <cfwddx> tag itself:
Exception during WDDX operation.
java.io.IOException: Invalid cast exception for WDDX recordset.
java.io.IOException: Invalid cast exception for WDDX recordset
at coldfusion.wddx.RecordSetSerializer.writeObject(WddxObjectSerializerFactory.java:346)
at coldfusion.wddx.WddxOutputStream.writeObject(WddxOutputStream.java:310)
at coldfusion.wddx.WddxOutputStream.writeDictionary(WddxOutputStream.java:525)
at coldfusion.wddx.DictionarySerializer.writeObject(WddxObjectSerializerFactory.java:300)
at coldfusion.wddx.WddxOutputStream.writeObject(WddxOutputStream.java:310)
at coldfusion.wddx.WddxOutputStream.writeDictionary(WddxOutputStream.java:525)
at coldfusion.wddx.DictionarySerializer.writeObject(WddxObjectSerializerFactory.java:300)
at coldfusion.wddx.WddxOutputStream.writeObject(WddxOutputStream.java:310)
at coldfusion.wddx.WddxSerializer.serialize(WddxSerializer.java:254)
at coldfusion.tagext.lang.WddxTag.serialize(WddxTag.java:285)
at coldfusion.tagext.lang.WddxTag.doStartTag(WddxTag.java:149)
at coldfusion.runtime.CfJspPage._emptyTag(CfJspPage.java:1908)
......
Obviously something wasn’t being cast correctly in the struct, thereby making it fail when trying to convert it to WDDX.
Being that the structure I’m converting to WDDX is very complex, I basically went down the path of doing StructDelete()’s on parts of it until I narrowed down the problem to a SQL Server query (the only such type within the report). I played around with <cfparam>’s in the bean where that query was set using getters and setters thinking by trying to precast that particular query in the struct before adding it. This unfortunately didn’t work, and I didn’t really think that it would given past experience, but it was a necessary step just to make sure it wasn’t something I was doing wrong somewhere.
Finally I remembered the database which the query was coming from was the database which I’d been using to evaluate the jTDS JDBC drivers with. It seemed strange that a JDBC driver could screw-up casting, but just for troubleshooting sake, I went ahead and switched the DSN over to the Microsoft SQL Server JDBC Driver. I ran the process again, and what do you know, that fixed the problem.
When Googling for “Invalid cast exception for WDDX recordset” there are basically no relevant links, so I thought I’d post a bit about it in case someone else runs into this problem in the future.
I finally arrived back home from Washington DC at around 10 PM last night, and finally had a chance to post the photos today. A word of warning about the CFUNITED photos– I was learning how to use a new camera as well as try not to distract people using the flash, so they aren’t the best photos. Joel Spolosky is a pretty high-energy bouncy guy, so all of his photos are blurred for instance.
Anyhow, here are my photos from CFUNITED, as well as other photos I took while touring around Washington DC.
I’ll try to post a bit later in the week about the conference, and some reflection on a few eyebrow raising things such as the MySpace Keynote, etc.