Cam Sagemaker dynamically allocate resources based on the load? For example, how easy would it be to run 5000 models in parallel? How does parameter tuning come into play?
You can certainly tune many models in parallel. You can set "Maximum number of parallel training jobs" for hyper-parameter tuning, and many jobs will run at the same time
Parallel tuning might not be the best idea however. Bayesian learning can be used to speed up tuning, but the next step relies on the previous step, making parallel's usefulness limited for Bayesian tuning. See https://docs.aws.amazon.com/sagemaker/latest/dg/automatic-model-tuning-considerations.html#automatic-model-tuning-parallelism
In terms of training, there is no built-in support for scaling. You can run a single training job on many machines (see "instance count"), or run many training jobs in parallel (by making many API calls), or use something like https://automl.github.io/auto-sklearn/master/, which would run many models in one training job
I'm trying to run H2O xgboost on r4.8x large. But it's taking too long to run (15+ hrs as opposed to 4 hours for GBM with same hyperparameter grid size).
Knowing that XGBoost uses cache optimization, is there any particular instance type that works best for H2O's XGBoost implementation?
My training data has 28K rows with 150 binary columns. And I'm running a grid search.
Changing your EC2 instance won't necessarily make it faster. You need to understand where is the bottleneck. Review the logs and see what takes time on GBM vs XGBoost. Is XGBoost creating deeper trees or more trees? It could be your settings are different between the two algorithms. Check that all the hyperparameters are similar (close as possible).
Also, XGBoost uses memory external to H2O's JVM. As mentioned in FAQ of H2O's XGBoost docs, try adding -extramempercent 120 and lowering your H2O memory.
I have a mini project for my new course in Tensorflow for this semester with random topics. Since I have some background on Convolution Neuron Network, I intend to use it for my project. My computer can only run CPU version of TensorFlow.
However, as a new bee, I realize that there are a lot of topics such that MNIST, CIFAR-10, etc, thus I don't know which suitable topic I should pick out from them. I only have two weeks left. It would be great if the topic is not too complicated but too not easy for study because it matchs my intermediate level.
In your experience, could you give me some advice about the specific topic I should do for my project?
Moreover, it would be better if in this topic I can provide my own data to test my training, because my professor said that it is a plus point to get A grade in my project.
Thanks in advance,
I think that to answer this question you need to properly evaluate the marking criteria for your project. However, I can give you a brief overview of what you've just mentioned.
MNIST: MNIST is a Optical Character Recognition task for individual numbers 0-9 in images size 28px square. This is considered the "Hello World" of CNNs. It's pretty basic and might be too simplistic for your requirements. Hard to gauge without more information. Nonetheless, this will run pretty quickly with CPU Tensorflow and the online tutorial is pretty good.
CIFAR-10: CIFAR is a much bigger dataset of objects and vehicles. The image sizes are 32px square so individual image processing isn't too bad. But the dataset is very large and your CPU might struggle with it. It takes a long time to train. You could try training on a reduced dataset but I don't know how that would go. Again, depends on your course requirements.
Flowers-Poets: There is the Tensorflow for Poets re-training example which might not be suitable for your course, you could use the flowers dataset to build your own model.
Build-your-own-model: You could use tf.Layers to build your own network and experiment with it. tf.Layers is pretty easy to use. Alternatively you could look at the new Estimators API that will automate a lot of the training processes for you. There are a number of tutorials (of varying quality) on the Tensorflow website.
I hope that helps give you a run-down of what's out there. Other datasets to look at are PASCAL VOC and imageNet (however they are huge!). Models to look at experimenting with may include VGG-16 and AlexNet.
I am working on Distributed Tensorflow, particularly the implementation of Reinspect model using Distributed Tensorflow given in the following paper https://github.com/Russell91/TensorBox .
We are using Between-graph-Asynchronous implementation of Distributed tensorflow settings but the results are very surprising. While bench marking, we have come to see that Distributed training takes almost more than 2 times more training time than a single machine training. Any leads about what could be happening and what else could be tried be would be really appreciated. Thanks
Note: There is a correction in the post, we are using between-graph implementation not in-graph implementation. Sorry for the mistake
In general, I wouldn't be surprised if moving from a single-process implementation of a model to a multi-machine implementation would lead to a slowdown. From your question, it's not obvious what might be going on, but here are a few general pointers:
If the model has a large number of parameters relative to the amount of computation (e.g. if it mostly performs large matrix multiplications rather than convolutions), then you may find that the network is the bottleneck. What is the bandwidth of your network connection?
Are there a large number of copies between processes, perhaps due to unfortunate device placement? Try collecting and visualizing a timeline to see what is going on when you run your model.
You mention that you are using "in-graph replication", which is not currently recommended for scalability. In-graph replication can create a bottleneck at the single master, especially when you have a large model graph with many replicas.
Are you using a single input pipeline across the replicas or multiple input pipelines? Using a single input pipeline would create a bottleneck at the process running the input pipeline. (However, with in-graph replication, running multiple input pipelines could also create a bottleneck as there would be one Python process driving the I/O with a large number of threads.)
Or are you using the feed mechanism? Feeding data is much slower when it has to cross process boundaries, as it would in a replicated setting. Using between-graph replication would at least remove the bottleneck at the single client process, but to get better performance you should use an input pipeline. (As Yaroslav observed, feeding and fetching large tensor values is slower in the distributed version because the data is transferred via RPC. In a single process these would use a simple memcpy() instead.)
How many processes are you using? What does the scaling curve look like? Is there an immediate slowdown when you switch to using a parameter server and single worker replica (compared to a single combined process)? Does the performance get better or worse as you add more replicas?
I was looking at similar thing recently, and I noticed that moving data from grpc into Python runtime is slower than expected. In particular consider following pattern
add_op = params.assign_add(update)
...
sess.run(add_op)
If add_op lies on a different process, then sess.run adds a decoding step that happens at rate of 50-100 MB/second.
Here's a benchmark and relevant discussion
I am working on a project that deals with analyzing a very large amount of data, so I discovered MapReduce fairly recently, and before i dive any further into it, i would like to make sure my expectations are correct.
The interaction with the data will happen from a web interface, so response time is critical here, i am thinking a 10-15 second limit. Assuming my data will be loaded into a distributed file system before i perform any analysis on it, what kind of a performance can i expect from it?
Let's say I need to filter a simple 5GB XML file that is well formed, has a fairly flat data structure and 10,000,000 records in it. And let's say the output will result in 100,000 records. Is 10 seconds possible?
If it, what kind of hardware am i looking at?
If not, why not?
I put the example down, but now wish that I didn't. 5GB was just a sample that i was talking about, and in reality I would be dealing with a lot of data. 5GB might be data for one hour of the day, and I might want to identify all the records that meet a certain criteria.
A database is really not an option for me. What i wanted to find out is what is the fastest performance i can expect out of using MapReduce. Is it always in minutes or hours? Is it never seconds?
MapReduce is good for scaling the processing of large datasets, but it is not intended to be responsive. In the Hadoop implementation, for instance, the overhead of startup usually takes a couple of minutes alone. The idea here is to take a processing job that would take days and bring it down to the order of hours, or hours to minutes, etc. But you would not start a new job in response to a web request and expect it to finish in time to respond.
To touch on why this is the case, consider the way MapReduce works (general, high-level overview):
A bunch of nodes receive portions of
the input data (called splits) and do
some processing (the map step)
The intermediate data (output from
the last step) is repartitioned such
that data with like keys ends up
together. This usually requires some
data transfer between nodes.
The reduce nodes (which are not
necessarily distinct from the mapper
nodes - a single machine can do
multiple jobs in succession) perform
the reduce step.
Result data is collected and merged
to produce the final output set.
While Hadoop, et al try to keep data locality as high as possible, there is still a fair amount of shuffling around that occurs during processing. This alone should preclude you from backing a responsive web interface with a distributed MapReduce implementation.
Edit: as Jan Jongboom pointed out, MapReduce is very good for preprocessing data such that web queries can be fast BECAUSE they don't need to engage in processing. Consider the famous example of creating an inverted index from a large set of webpages.
A distributed implementation of MapReduce such as Hadoop is not a good fit for processing a 5GB XML
Hadoop works best on large amounts of data. Although 5GB is a fairly big XML file, it can easily be processed on a single machine.
Input files to Hadoop jobs need to be splittable so that different parts of the file can be processed on different machines. Unless your xml is trivially flat, the splitting of the file will be non deterministic so you'll need a pre processing step to format the file for splitting.
If you had many 5GB files, then you could use hadoop to distribute the splitting. You could also use it to merge results across files and store the results in a format for fast querying for use by your web interface as other answers have mentioned.
MapReduce is a generic term. You probably mean to ask whether a fully featured MapReduce framework with job control, such as Hadoop, is right for you. The answer still depends on the framework, but usually, the job control, network, data replication, and fault tolerance features of a MapReduce framework makes it suitable for tasks that take minutes, hours, or longer, and that's probably the short and correct answer for you.
The MapReduce paradigm might be useful to you if your tasks can be split among indepdent mappers and combined with one or more reducers, and the language, framework, and infrastructure that you have available let you take advantage of that.
There isn't necessarily a distinction between MapReduce and a database. A declarative language such as SQL is a good way to abstract parallelism, as are queryable MapReduce frameworks such as HBase. This article discusses MapReduce implementations of a k-means algorithm, and ends with a pure SQL example (which assumes that the server can parallelize it).
Ideally, a developer doesn't need to know too much about the plumbing at all. Erlang examples like to show off how the functional language features handle process control.
Also, keep in mind that there are lightweight ways to play with MapReduce, such as bashreduce.
I recently worked on a system that processes roughly 120GB/hour with 30 days of history. We ended up using Netezza for organizational reasons, but I think Hadoop may be an appropriate solution depending on the details of your data and queries.
Note that XML is very verbose. One of your main cost will reading/writing to disk. If you can, chose a more compact format.
The number of nodes in your cluster will depend on type and number of disks and CPU. You can assume for a rough calculation that you will be limited by disk speed. If your 7200rpm disk can scan at 50MB/s and you want to scan 500GB in 10s, then you need 1000 nodes.
You may want to play with Amazon's EC2, where you can stand up a Hadoop cluster and pay by the minute, or you can run a MapReduce job on their infrastructure.
It sounds like what you might want is a good old fashioned database. Not quite as trendy as map/reduce, but often sufficient for small jobs like this. Depending on how flexible your filtering needs to be, you could either just import your 5GB file into a SQL database, or you could implement your own indexing scheme yourself, by either storing records in different files, storing everything in memory in a giant hashtable, or whatever is appropriate for your needs.