Re: Storing/retrieving time series with hadoop
We use Hadoop to warehouse time series data, and run analytics on them. Being able to parallelize our analytics jobs, and scale up the cluster as needed for the data, turned out to be a big win. However, we rolled our own storage solution. At the time when we started on this project, there were no good solutions for storing time series (maybe there are right now). I investigated HBase, but it was optimized for retrieving just the latest values, not the entire time series for analysis. We also investigated Pig, but it was too early in the project's life, and didn't support everything we wanted. As for latency - with S3 it can be significant, depending on how you lay out your data; we have a separate caching layer just to speed up data retrieval for graph drawing. I haven't tried HDFS over clustered hard drives, though; it might be fast enough for your purposes. Cheers, Robert Brock Judkins wrote: Hi list, I am researching hadoop as a possible solution for my company's data warehousing solution. My question is whether hadoop, possibly in combination with Hive or Pig, is a good solution for time-series data? We basically have a ton of web analytics to store that we display both internally and externally. For the time being I am storing timestamped data points in a huge MySQL table, but I know this will not scale very far (although it's holding up ok at almost 90MM rows). I am aware that hadoop can scale insanely large (larger than I need), but does anyone have experience using it to draw charts based on time series with fairly low latency? Thanks! Brock
Re: Storing/retrieving time series with hadoop
Hey Brock I used Cascading quite extensively with time series data. Along with the standard function/filter/aggregator operations in the Cascading processing model, there is what we call a buffer. Its really just a user friendly Reduce that integrates well with other operations and offers up a sliding window across your grouped data. Quite useful for running averages or filling in missing intervals etc. Plus there are handy operations for switching from text time strings to long time stamps and back etc.. YMMV cheers, ckw On Jan 7, 2009, at 5:03 PM, Brock Judkins wrote: Hi list, I am researching hadoop as a possible solution for my company's data warehousing solution. My question is whether hadoop, possibly in combination with Hive or Pig, is a good solution for time-series data? We basically have a ton of web analytics to store that we display both internally and externally. For the time being I am storing timestamped data points in a huge MySQL table, but I know this will not scale very far (although it's holding up ok at almost 90MM rows). I am aware that hadoop can scale insanely large (larger than I need), but does anyone have experience using it to draw charts based on time series with fairly low latency? Thanks! Brock -- Chris K Wensel ch...@wensel.net http://www.cascading.org/ http://www.scaleunlimited.com/
Storing/retrieving time series with hadoop
Hi list, I am researching hadoop as a possible solution for my company's data warehousing solution. My question is whether hadoop, possibly in combination with Hive or Pig, is a good solution for time-series data? We basically have a ton of web analytics to store that we display both internally and externally. For the time being I am storing timestamped data points in a huge MySQL table, but I know this will not scale very far (although it's holding up ok at almost 90MM rows). I am aware that hadoop can scale insanely large (larger than I need), but does anyone have experience using it to draw charts based on time series with fairly low latency? Thanks! Brock
