How much RAM do I need for MongoDB?
MongoDB requires approximately 1GB of RAM per 100.000 assets. If the system has to start swapping memory to disk, this will have a severely negative impact on performance, and should be avoided.
Does MongoDB use RAM?
MongoDB, in its default configuration, will use will use the larger of either 256 MB or ½ of (ram – 1 GB) for its cache size. But MongoDB uses both its internal cache and the system’s file system cache.
Why does MongoDB use memory?
MongoDB keeps all data in its caches for performance reason and it will not release them until its memory increase to 50% of (system RAM – 1 GB) (default). This means its memory will increase continuously when you write/read data from it. You can find additional information documented here.
How big is a 16Mb MongoDB document?
With its 16Mb limit, a MongoDB document can easily store around 2 million values of 64-bit numbers (also dates and booleans).
How much memory does MongoDB use per day?
So it seems that the actual dataset size + its indexes are taking about 68GBs of that memory. Considering all these, I guess the memory usage is now pretty expected, good part being it’s completely okay to limit the WiredTiger cache size, since it handles I/O operations pretty efficiently (as described above).
Why is there a maximum document size in MongoDB?
The maximum document size helps ensure that a single document cannot use excessive amount of RAM or, during transmission, excessive amount of bandwidth. To store documents larger than the maximum size, MongoDB provides the GridFS API. See mongofiles and the documentation for your driver for more information about GridFS.
What’s the limit for the aggregation pipeline in MongoDB?
Pipeline stages have a limit of 100 megabytes of RAM. If a stage exceeds this limit, MongoDB will produce an error. To allow for the handling of large datasets, use the allowDiskUse option to enable aggregation pipeline stages to write data to temporary files.
What does the WiredTiger cache do in MongoDB?
The WiredTiger cache settings only controls the size of memory directly used by the WiredTiger storage engine (not the total memory used by mongod). Many other things are potentially taking memory in a MongoDB/WiredTiger configuration, such as the following: