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Type:
Bug
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Resolution: Done
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Priority:
Major - P3
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Affects Version/s: 1.6.0
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Component/s: Sharding
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Labels:None
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Environment:Two identical servers with:
* Ubuntu 9.10 64 bit (Linux vs8 2.6.31-22-server #60-Ubuntu SMP Thu May 27 03:42:09 UTC 2010 x86_64 GNU/Linux)
* Running on Dell 1950, with 24G ram and, Dual Intel Xeon L5335
It's a simple sharded setup. mongos, and the config server is running on the first server, and the second one only runs a mongodb instance.
Two identical servers with: * Ubuntu 9.10 64 bit (Linux vs8 2.6.31-22-server #60-Ubuntu SMP Thu May 27 03:42:09 UTC 2010 x86_64 GNU/Linux) * Running on Dell 1950, with 24G ram and, Dual Intel Xeon L5335 It's a simple sharded setup. mongos, and the config server is running on the first server, and the second one only runs a mongodb instance.
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ALL
mongos process crashes if we run multiple map reduce jobs in parallel. It works properly if those jobs are ran serially.
The issue is not intermittent. mongos will crash every time we try to execute the jobs in parallel.
Our flow is:
- Generate the selector/query A
- Run 3 map reduce jobs with query A
- Run a query with find().skip().limit().sort() with query A and sort by B
- Run a count() query with query A
we run these steps in parallel with 5 threads.
Map reduce jobs are meant to generate a simple groupby/count resultset.
map fn: function() {emit(this.FIELD,
{count:1});}; /* FIELD is: Make, Year, VehicleType for different jobs */
reduce fn: function(key, vals) {var t = 0; for (var i = 0; i < vals.length; i++) t += vals[i].count; return
;};