Hive lets you hot-deply UDF/jar, but I think that is a more simple. Each hive query is really its own map reduce job. HBASE is a running process.
http://www.javalobby.org/java/forums/t18345.html Hot loading java classes does work, but you have to design interfaces to deal with compile/time run time issues. Also Hot loading, has a big problem hot unloading! In my experience once you get a class 'hot loaded' hot unloading can not happen until you lose any references to objects of the class. I can imagine a situation where you load a filter with a small logic error, getting it unloaded and a new version loaded can be quite tricky. So hot loading is cool but on the flip side it involves writing a lot of code you did not need before. On Thu, Jan 14, 2010 at 11:00 AM, Leen Toelen <[email protected]> wrote: > Hi, > > is HBase able to add/load a jar to its classpath on the fly? It would be > neat to have a 'hot deploy' directory, much like felix fileinstall. > > Regards, > Leen > > On Thu, Jan 14, 2010 at 4:00 PM, Paul Ambrose <[email protected]> wrote: > >> Yes, add it to HBASE_CLASSPATH in $HBASE_HOME/conf/hbase-env.sh >> http://www.hbql.com/installation.html >> >> On Jan 14, 2010, at 1:39 AM, Sriram Muthuswamy Chittathoor wrote: >> >> > Could this be the reason as to why in HBQL something like this does not >> > work >> > " SELECT * FROM demo1 WITH SERVER FILTER WHERE f1:val2 > 100" >> > >> > Whereas "SELECT * FROM demo1 WITH CLIENT FILTER WHERE f1:val2 > 100" >> > works. >> > >> > I need to copy hbql jar to all the machines and set it in the class path >> > ? >> > >> > -----Original Message----- >> > From: [email protected] [mailto:[email protected]] On Behalf Of >> > stack >> > Sent: Wednesday, January 13, 2010 11:42 PM >> > To: [email protected] >> > Subject: Re: Data processing/filtering on the server >> > >> > Your custom code needs to be on the CLASSPATH of both server and client >> > so >> > it may need a restart of your servers after adding your new filter >> > serverside. We do not yet have dynamic loading of filters implemented. >> > There may be another issue where instead of passing class names, we >> > pass a >> > code -- saves on message sizes passed -- and your new class may not make >> > it >> > across because currently codes need to be added to the head of >> > HbaseObjectWritable. That said there is provision for when a code does >> > not >> > exist, we instead send over the class name. Maybe this will work for >> > you. >> > >> > St.Ack >> > >> > On Wed, Jan 13, 2010 at 9:38 AM, Sriram Muthuswamy Chittathoor < >> > [email protected]> wrote: >> > >> >> Thanks Edward. As an experiment I was trying to write my own filter >> > and >> >> use the scan.setFilter (..) method to set it. Is this even possible >> > as I >> >> got into issues -- started giving some region server exception. >> > Based on >> >> your response if the filtering is applied on the server side obviously >> > my >> >> local custom filter class cannot be used. Am I guessing it right ?? >> >> >> >> -----Original Message----- >> >> From: Edward Capriolo [mailto:[email protected]] >> >> Sent: Wednesday, January 13, 2010 11:00 PM >> >> To: [email protected] >> >> Subject: Re: Data processing/filtering on the server >> >> >> >> Filters are applied server side: >> >> >> >> >> >> >> > http://hadoop.apache.org/hbase/docs/current/api/org/apache/hadoop/hbase/ >> > filter/package-summary.html >> >> >> >> Edward >> >> On Wed, Jan 13, 2010 at 12:28 PM, Sriram Muthuswamy Chittathoor >> >> <[email protected]> wrote: >> >>> Hi: >> >>> >> >>> I am currently using the HBase client api to fetch the data rows and >> >>> process the rows on the client JVM. Is there a way to specify >> > filters >> >>> which will apply say on the region servers so that the data that is >> >>> returned to me is a filtered set. I don't want all the data rows to >> >>> travel on the wire from the server to the client JVM >> >>> >> >>> Sriram C >> >>> >> >>> This email is sent for and on behalf of Ivy Comptech Private >> > Limited. Ivy >> >> Comptech Private Limited is a limited liability company. >> >>> >> >>> This email and any attachments are confidential, and may be legally >> >> privileged and protected by copyright. If you are not the intended >> > recipient >> >> dissemination or copying of this email is prohibited. If you have >> > received >> >> this in error, please notify the sender by replying by email and then >> > delete >> >> the email completely from your system. >> >>> Any views or opinions are solely those of the sender. This >> > communication >> >> is not intended to form a binding contract on behalf of Ivy Comptech >> > Private >> >> Limited unless expressly indicated to the contrary and properly >> > authorised. >> >> Any actions taken on the basis of this email are at the recipient's >> > own >> >> risk. >> >>> >> >>> Registered office: >> >>> Ivy Comptech Private Limited, Cyber Spazio, Road No. 2, Banjara >> > Hills, >> >> Hyderabad 500 033, Andhra Pradesh, India. Registered number: 37994. >> >> Registered in India. A list of members' names is available for >> > inspection at >> >> the registered office. >> >>> >> >>> >> >> >> >> This email is sent for and on behalf of Ivy Comptech Private Limited. >> > Ivy >> >> Comptech Private Limited is a limited liability company. >> >> >> >> This email and any attachments are confidential, and may be legally >> >> privileged and protected by copyright. If you are not the intended >> > recipient >> >> dissemination or copying of this email is prohibited. If you have >> > received >> >> this in error, please notify the sender by replying by email and then >> > delete >> >> the email completely from your system. >> >> Any views or opinions are solely those of the sender. This >> > communication >> >> is not intended to form a binding contract on behalf of Ivy Comptech >> > Private >> >> Limited unless expressly indicated to the contrary and properly >> > authorised. >> >> Any actions taken on the basis of this email are at the recipient's >> > own >> >> risk. >> >> >> >> Registered office: >> >> Ivy Comptech Private Limited, Cyber Spazio, Road No. 2, Banjara Hills, >> >> Hyderabad 500 033, Andhra Pradesh, India. Registered number: 37994. >> >> Registered in India. A list of members' names is available for >> > inspection at >> >> the registered office. >> >> >> >> >> >> >
