More often than not, we see tomcat server log prints many warnings, and 2 are very common. After some tests and google, these are warning and will not impact tomcat a lot.
Jan 28, 2011 6:22:53 PM org.apache.tomcat.util.http.Parameters processParameters
WARNING: Parameters: Invalid chunk ignored.
Jan 28, 2011 6:23:11 PM org.apache.tomcat.util.http.Parameters processParameters
WARNING: Parameters: Character decoding failed. Parameter skipped.
java.io.CharConversionException: isHexDigit
Jan 28, 2011 6:42:54 PM org.apache.tomcat.util.http.Parameters processParameters
WARNING: Parameters: Character decoding failed. Parameter skipped.
java.io.CharConversionException: EOF
action.do?cmd=yourcmd&username=yourname&&password=yourpass (Invalid chunk ignored.)
action.do?cmd=yourcmd&username=yourname&%password=yourpass (Character decoding failed...isHexDigit)
action.do?cmd=yourcmd&username=yourname%&password=yourpass (Character decoding failed...EOF)
These characters are used to URL specific function like “&” id used to differentiate various URL parameters. This generates a “null” value for the parameter you will try to retrieve in Servlet. % is URL reserved character for urlencode.
Solution:
The simple way to get over this problem is to massage your Special Character String with “escape()” funtion in javascript, so & will get encoded to %26, % will get encoded to %25. In Java, URLEncode can also do the same protection.
Friday, January 28, 2011
Tuesday, January 25, 2011
Group buying
Recently I got many deals from group buying sites like 50% off $20 Amazon gift card from LivingSocial, $4 AMC movie ticket from mamapedia.com, Los Gatos museum family membership from groupon.com. Also there are many news regarding group buying web sites (which are expected to have huge marketing share from local advertisement, a billion dollar web tread) , including today Google launched Google Offers from iGoogle, after groupon.com denied Google's 6 billion acquisition request, also LivingSocial promoted its web site traffic with Amazon overwhelming gift card offer. The concept (tuangou, team buying, group buying, or group shopping) was originated from China, and There are more than 800 tuangou websites in China.
So what is group buying? See http://en.wikipedia.org/wiki/Tuangou
Here is some excerpt to discuss about group buying characteristics, and also a new model from an e-commerce company called Next Jump.
The most notable characteristic of all those intermediaries is the selected deals' orientation towards local markets, bound to cities and towns. Leaders include Groupon, which has 79% of the market share, LivingSocial (8% share) and BuyWithMe(3% share)[5]
In 2010, several new business models for group buying have been proposed, emerging from the overall popularization of micropayments. After the offer's deadline, buyers make direct purchases from the vendors' web sites, achieving higher mutual benefits. The most prominent company in this area is Next Jump, which handles a line called 'Overwhelming Offers', offered through many loyalty programs, including Borders Rewards, MasterCard Marketplace, and their own website. This method does not charge percentage fees, but uses reservations as pledges of interest for after-deadline purchases.
There is another group buying site which is a deal aggregator from other popular group buying sites. The example is Yipit.
This article http://tomuse.com/group-buying-sites-coupon-deals-discount-savings/ compares many group buying sites from many aspects including countries, cities, referral incentive, reward points, mobile app (on-the-go), unique features, gifts etc.
So what is group buying? See http://en.wikipedia.org/wiki/Tuangou
Here is some excerpt to discuss about group buying characteristics, and also a new model from an e-commerce company called Next Jump.
The most notable characteristic of all those intermediaries is the selected deals' orientation towards local markets, bound to cities and towns. Leaders include Groupon, which has 79% of the market share, LivingSocial (8% share) and BuyWithMe(3% share)[5]
In 2010, several new business models for group buying have been proposed, emerging from the overall popularization of micropayments. After the offer's deadline, buyers make direct purchases from the vendors' web sites, achieving higher mutual benefits. The most prominent company in this area is Next Jump, which handles a line called 'Overwhelming Offers', offered through many loyalty programs, including Borders Rewards, MasterCard Marketplace, and their own website. This method does not charge percentage fees, but uses reservations as pledges of interest for after-deadline purchases.
There is another group buying site which is a deal aggregator from other popular group buying sites. The example is Yipit.
This article http://tomuse.com/group-buying-sites-coupon-deals-discount-savings/ compares many group buying sites from many aspects including countries, cities, referral incentive, reward points, mobile app (on-the-go), unique features, gifts etc.
Wednesday, January 19, 2011
ACE TCP Offload
This white paper provides more details about 2 options regarding ACE TCP offload, namely TCP connection reuse and SSL Acceleration.
TCP connection reuse - TCP connections pooling to eliminate the server connection processing bottleneck
SSL Acceleration - Offloading SSL processing onto the ACE Module
HTTP persistent connections, also called HTTP keep-alive, or HTTP connection reuse, is the idea of using the same TCP connection to send and receive multiple HTTP requests/responses, as opposed to opening a new one for every single request/response pair. Using persistent connections is very important for improving HTTP performance. The advantages are even more obvious with HTTPS or HTTP over SSL/TLS. There, persistent connections may reduce the number of costly SSL/TLS handshake to establish security associations, in addition to the initial TCP connection set up.
See more info about HTTP keep-alive in JDK http://download.oracle.com/javase/1.5.0/docs/guide/net/http-keepalive.html
SSL hardware accelerator is performing SSL offloading, because part of the SSL processing is “offloaded” from the server’s CPU to the card’s co-processor. The term “offloading,” however, is generally used to describe an appliance or a completely separate computer that performs all SSL processing, so that the SSL load is taken off of the Web server completely.
SSL offloading can greatly increase the performance of your secure Web servers, thus increasing customer satisfaction. However, offloading means the SSL connection extends only from client to offloader, not from client to server. Data passes across the network unencrypted from offloader to server.
TCP connection reuse - TCP connections pooling to eliminate the server connection processing bottleneck
SSL Acceleration - Offloading SSL processing onto the ACE Module
HTTP persistent connections, also called HTTP keep-alive, or HTTP connection reuse, is the idea of using the same TCP connection to send and receive multiple HTTP requests/responses, as opposed to opening a new one for every single request/response pair. Using persistent connections is very important for improving HTTP performance. The advantages are even more obvious with HTTPS or HTTP over SSL/TLS. There, persistent connections may reduce the number of costly SSL/TLS handshake to establish security associations, in addition to the initial TCP connection set up.
See more info about HTTP keep-alive in JDK http://download.oracle.com/javase/1.5.0/docs/guide/net/http-keepalive.html
SSL hardware accelerator is performing SSL offloading, because part of the SSL processing is “offloaded” from the server’s CPU to the card’s co-processor. The term “offloading,” however, is generally used to describe an appliance or a completely separate computer that performs all SSL processing, so that the SSL load is taken off of the Web server completely.
SSL offloading can greatly increase the performance of your secure Web servers, thus increasing customer satisfaction. However, offloading means the SSL connection extends only from client to offloader, not from client to server. Data passes across the network unencrypted from offloader to server.
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