Updated: July 30th, 2021

The Problem

I am throwing up a quick post about a relatively cryptic error that Solr started throwing the other day here at Plaxo. After happily running for a few days, I suddenly started getting pages about failed Solr indexing.

Upon closer examination, I saw the following repeatedly in the log file:

catalina.2009-09-18.log:SEVERE: java.io.IOException: directory 'DATADIR/index'
exists and is a directory, but cannot be listed: list() returned null

I tried to see if sending an OPTIMIZE command would help but the server returned the same response.

Digging Deeper

The reason was these errors was quite simple – Solr was running …

Updated: September 8th, 2009

Well, it looks like the wait is over. I have been waiting for almost 5 years for a new phone that is good enough to make the switch from Samsung A900 (which has free tethering). Don't even get me started on the iPhone and its outrageous monopoly with AT&T. Android and the growing multitude of devices running it is, however, completely different business. Android offers unparallel freedom and I truly believe it will be the top phone OS within a few years as more and more Android phones are introduced to the market.

But where was I? I have been closely following Android news since its inception, then the introduction of the first phone – T-Mobile G1 (aka HTC Dream), …

Updated: July 30th, 2021

In the past few weeks I've been implementing advanced search at Plaxo, working quite closely with Solr enterprise search server. Today, I saw this relatively detailed comparison between Solr and its main competitor Sphinx (full credit goes to StackOverflow user mausch who had been using Solr for the past 2 years). For those still confused, Solr and Sphinx are similar to MySQL FULLTEXT search, or for those even more confused, think Google (yeah, this is a bit of a stretch, I know).

Similarities

• Both Solr and Sphinx satisfy all of your requirements. They're fast and designed to index and search large bodies of data efficiently.
• Both have a long list of high-traffic sites using them (Solr, Sphinx

…

Read the rest of this article »

Updated: January 16th, 2010

Introduction

I love Delicious. It allows me to store my bookmarks, tag and search them, and, best of all, have access to them from anywhere on the web.

Searching bookmarks by keyword is easy – just enter a bunch of keywords into the search page and off you go but what if you want to confine your results to a certain domain? The main reason I wanted to do it personally is so that I could see all pages of my site bookmarked by Delicious users and the corresponding number of bookmarks. However, the only url based search Delicious offered was a full url lookup:

This search is very limited – it accepts only a full url to …

OK, maybe you did know them – just see for yourself.

Introduction

The tricks I am going to describe allow you to create unique gmail addresses that still hit your existing gmail inbox, without actually making new gmail accounts.

This can be useful in a variety of situations when you need to use multiple email addresses without having the pain of maintaining them, such as

• using unique emails while registering for the same service more than once (say, paypal)
• giving out a unique email address to see if you start getting spam to it later – that way you know exactly who to blame for it
• more generally, easily create email rules to sort incoming emails into folders, delete them,

…

Read the rest of this article »

Updated: January 30th, 2013

The Problem

My fiancée Emilie has had her Palm Pre for about 2 weeks now, and one specific problem that started showing up last week has been incredibly annoying, causing us all kinds of trouble.

After Emilie got the phone, she added 3 email accounts – Gmail, Hotmail, and Yahoo. One day, after sending an email through the Pre, a popup showed up that said "Error sending" followed by the subject of that specific email. Swiping the error away didn't help – it just came back 5 minutes later. In fact, it has been coming back every 5 minutes of every day since, lighting up the screen each time. Thus, not only it was annoying, but it was running down …

Updated: October 6th, 2009

Mom sent me this picture the other day, taken in Kharkov, Ukraine, my home city.

My question is… wtf? I'm assuming the truck started where the road was – what kind of speeds were involved here? Those trains usually go at speeds around 15-25mph… No word on the injuries.

…

Updated: September 16th, 2012

Introduction

StackOverflow is an amazing site for coding questions. It was created by Joel Spolsky of joelonsoftware.com, Jeff Atwood of codinghorror.com, and some other incredibly smart guys who truly care about user experience. I have been a total fan of SO since it went mainstream and it's now a borderline addiction (you can see my StackOverflow badge on the right sidebar).

The Story

Update 6/21/09: This server is currently under very heavy load (10-200), even with caching plugins enabled. Please bear with me as I try to resolve the situation.

Feel free to bookmark this page and return to it later when the fires have been put out.

Update 06/21/09: I think I've got the situation …

Updated: October 6th, 2009

Introduction

Every time I have to deal with svn:externals in SVN, I forget the command line syntax. Every single damn time. Normally, I use SVN GUI clients, such as SmartSVN, which make it very simple to add an svn:externals property. But for command line, it always takes looking at 25 different sites on google, which are all incredibly unhelpful for this question for some reason. Trying "svn help propset" on the command line was bloated and equally useless.

So this time I needed to write it down and make sure everyone who needed help with svn:externals would find exactly what they need here. I hope this page will soon come up on top of all the unhelpful results on …

Updated: September 27th, 2009

Introduction

Welcome to part 2 of the Essential Firefox Extensions And Tips – A Comprehensive Guide series. In this article I’m going to describe a number of time saving pragmatic extensions that make me a better, faster, more efficient browser user (browserer?).

Pragmatic Extensions

All-in-One Gestures

All-in-One Gestures introduces customizable gestures for all kinds of actions. To perform a gesture, hold the right (by default) button and move the mouse in the specified direction, drawing the needed shape.

I use it mostly for 3 things: history back/forward and close tab (see below). Once you start using gestures, there is no …

Updated: June 10th, 2009

* Lightning Fast is a blatant exaggeration. Got you to look though, didn't it?

Introduction

Whether you are a web developer or a self-hosting business owner, the only excuse for not activating compression capabilities of your web server can be that you didn't know about it. And now that you are reading this, there is no excuse left at all.

Here is how big a single page of this blog was before compression was enabled on CSS and Javascript files (computed by YSlow):

And here it is after compression:

As you see, the difference is quite substantial – almost 30% savings.

Compressing your HTML, XML, Javascript, CSS, etc pages will mean less data transferred between the server and the …

I've been looking for a new laptop and started looking at Lenovo Thinkpads (W500) and Dell Latitudes and Precisions. I was worried that I might not like the look and feel, so I tried looking up their US laptop return policy.

Dell's return policy was found in about 5 seconds.

Lenovo's site, google, bing, or any other resource, however, proved to be useless while looking up their US return policy (all I could find was their Australian policy for whatever reason). Lenovo tried VERY hard to bury it, and I was only able to find it after tweeting at lenovosocial, which at first gave me the wrong policy by mistake (it was a 30 days, no questions asked guarantee). …

The Problem

If you use VNC to remotely connect to your machines and are having problems with certain applications not showing changes (redrawing), this will, hopefully, solve the problem for you.

The symptoms are simple: you load a program but only the program outline and maybe the first frame would show up. After that, nothing would update, even though the user in front of the remote computer can see everything updating fine. For me, it is happening with all Java based programs (SmartSVN, Charles – amazing program btw!, etc). Here's what's happening to my Charles application – it never even sent the first frame, simply showing the desktop and not updating:

The problem may be confined to RealVNC …

The Problem

I use a lot of extensions. A LOT. They slow down my Firefox while giving something useful in return. Most of them are harmless and do not affect the speed too much but there are select few that are just CPU, memory, and performance hogs.

Until Firefox gets an extension manager that can show what the impact from each extension on time/CPU/memory is, one can resort to guessing, disabling, testing, and looking for clues to find these conniving little bastards.

Anyway, so where was I? Recently, my Firefox became increasingly unresponsive, especially when switching tabs. After some time, it was a pain to switch tabs altogether, so I had to resort to restarting the browser, only to …

Introduction

A question I recently saw on Stack Overflow titled Faster way to delete matching [database] rows? prompted me to organize my thoughts and observations on the subject and quickly jot them down here.

Here is the brief description of the task: say, you have 2 MySQL tables a and b. The tables contain the same type of data, for example log entries. Now you want to delete all or a subset of the entries in table a that exist in table b.

Solutions Suggested By Others

DELETE FROM a WHERE EXISTS (SELECT b.id FROM b WHERE b.id = a.id);

DELETE a