PyD4M for Accumulo

2021-09-10 Thread Kepner, Jeremy - LLSC - MITLL
Accumulo Colleagues, We’re excited to announce that version 1.2 of the Python implementation of D4M (D4M.py) has been released on github (https://github.com/Accla/D4M.py). In particular, this version of D4M.py includes Accumulo bindings for reading and writing Accumulo tables as D4M associati

RE: [External] Re: [EXTERNAL EMAIL] - Re: accumulo and hdfs data locality

2021-09-10 Thread Ligade, Shailesh [USA]
Thanks Appreciated! -S From: Christopher Sent: Friday, September 10, 2021 9:15 AM To: accumulo-user Subject: [External] Re: [EXTERNAL EMAIL] - Re: accumulo and hdfs data locality One correction to what Mike said. The last location column doesn't store where it was last hosted. The current loc

Re: [EXTERNAL EMAIL] - Re: accumulo and hdfs data locality

2021-09-10 Thread Michael Wall
Yep, thanks for the correction Christopher. On Fri, Sep 10, 2021 at 9:15 AM Christopher wrote: > One correction to what Mike said. The last location column doesn't store > where it was last hosted. The current location column does that. Rather, > the last location column stores where it was host

Re: [EXTERNAL EMAIL] - Re: accumulo and hdfs data locality

2021-09-10 Thread Christopher
One correction to what Mike said. The last location column doesn't store where it was last hosted. The current location column does that. Rather, the last location column stores where it was hosted when it last wrote to HDFS. The goal is what Mike said: it tries to provide a mechanism for preservin

Re: [EXTERNAL EMAIL] - Re: accumulo and hdfs data locality

2021-09-10 Thread Christopher
Frequent compactions can help maintain locality, as can a custom balancer and volume chooser. However, the impact of more frequent compactions on query performance and other system metrics would need to be considered. Achieving optimal locality may not be that important overall. Side note: your ma

Re: [EXTERNAL EMAIL] - Re: accumulo and hdfs data locality

2021-09-10 Thread Michael Wall
If a tablet moves, the data files in HDFS do not go with it. However, during the next compaction one copy of the rfile should be written locally. Note, the metadata has a last column for each tablet, to record where the table was last hosted. On startup, Accumulo will try to assign a tablet to t

RE: [EXTERNAL EMAIL] - Re: accumulo and hdfs data locality

2021-09-10 Thread Shailesh Ligade
Thank you, Is there way to maintain that data locality, I mean over time with table splitting, hdfs rebalancing etc we may not have data locality… Thanks again -S From: Christopher Sent: Friday, September 10, 2021 8:40 AM To: accumulo-user Subject: [EXTERNAL EMAIL] - Re: accumulo and hdfs da

Re: accumulo and hdfs data locality

2021-09-10 Thread Christopher
Data locality and simplified deployments are the only reasons I can think of. Accumulo doesn't do anything particularly special for data locality, but typically, an HDFS client (like Accumulo servers) will (or can be configured to) write one copy of any new blocks locally, which should permit effic

accumulo and hdfs data locality

2021-09-10 Thread Shailesh Ligade
Hello I am suing Hadoop 3.3 and accumulo 1.10. Does accumulo take advantage of Hadoop data locality? What are the other benefits of having tserver and datanode process on the same instance? -S