You could also implement a constraint to notify an external system when a row is updated.
On Wed, Dec 2, 2015, 22:54 Josh Elser <josh.el...@gmail.com> wrote: > oops :) > > [1] http://fluo.io/ > > Josh Elser wrote: > > Hi Thai, > > > > There is no out-of-the-box feature provided with Accumulo that does what > > you're asking for. Accumulo doesn't provide any functionality to push > > notifications to other systems. You could potentially maintain other > > tables/columns in which you maintain the last time a row was updated, > > but the onus is on your "other services" to read the table to find out > > when a change occurred (which is probably not scalable at "real time"). > > > > There are other systems you could likely leverage to solve this, > > depending on the durability and scalability that your application needs. > > > > For a system "close" to Accumulo, you could take a look at Fluo [1] > > which is an implementation of Google's "Percolator" system. This is a > > system based on throughput rather than low-latency, so it may not be a > > good fit for your needs. There are probably other systems in the Apache > > ecosystem (Kafka, Storm, Flink or Spark Streaming maybe?) that are be > > helpful to your problem. I'm not an expert on these to recommend on (nor > > do I think I understand your entire architecture well enough). > > > > Thai Ngo wrote: > >> Hi list, > >> > >> I have a use-case when existing rows in a table will be updated by an > >> internal service. Data in a row of this table is composed of 2 parts: > >> 1st part - immutable and the 2nd one - will be updated (filled in) a > >> little later. > >> > >> Currently, I have a need of knowing when and which rows will be updated > >> in the table so that other services will be wisely start consuming the > >> data. It will make more sense when I need to consume the data in near > >> realtime. So developing a notification function or simpler - a trigger > >> is what I really want to do now. > >> > >> I am curious to know if someone has done similar job or there are > >> features or APIs or best practices available for Accumulo so far. I'm > >> thinking of letting the internal service which updates the data notify > >> us whenever it updates the data. > >> > >> What do you think? > >> > >> Thanks, > >> Thai >
