Babulal commented on CARBONDATA-1281:

Can you please try option carbon.tempstore.locations
In carbon.properties . It will accept mutiple disks to local store/sort.


> Disk hotspot found during data loading
> --------------------------------------
>                 Key: CARBONDATA-1281
>                 URL: https://issues.apache.org/jira/browse/CARBONDATA-1281
>             Project: CarbonData
>          Issue Type: Improvement
>          Components: core, data-load
>    Affects Versions: 1.1.0
>            Reporter: xuchuanyin
>          Time Spent: 1h
>  Remaining Estimate: 0h
> # Scenario
> Currently we have done a massive data loading. The input data is about 71GB 
> in CSV format,and have about 88million records. When using carbondata, we do 
> not use any dictionary encoding. Our testing environment has three nodes and 
> each of them have 11 disks as yarn executor directory. We submit the loading 
> command through JDBCServer.The JDBCServer instance have three executors in 
> total, one on each node respectively. The loading takes about 10minutes 
> (+-3min vary from each time).
> We have observed the nmon information during the loading and find:
> 1. lots of CPU waits in the first half of loading;
> 2. only one single disk has many writes and almost reaches its bottleneck 
> (Avg. 80M/s, Max. 150M/s on SAS Disk)
> 3. the other disks are quite idel
> # Analyze
> When do data loading, carbondata read and sort data locally(default scope) 
> and write the temp files to local disk. In my case, there is only one 
> executor in one node, so carbondata write all the temp file to one 
> disk(container directory or yarn local directory), thus resulting into single 
> disk hotspot.
> # Modification
> We should support multiple directory for writing temp files to avoid disk 
> hotspot.
> Ps: I have improved this in my environment and the result is pretty 
> optimistic: the loading takes about 6minutes (10 minutes before improving).

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