I have some docplex models that I need to populate solution pools for them at the same time. All the models have a lazy constraint callback. My problem is when I start solving these models at the same time ,by running them on different consoles, their runtime increases. 1 single model can populate in 200 seconds but when I start solving 3 different models at the same time the runtime for that model becomes 2000 seconds. assuming that I have enough CPU and memory, why is this happening? and how can I avoid it and get the lower runtime?
You could try to limit each solve to 1 thread by using threads.
As an example
from docplex.mp.model import Model
mdl = Model(name='buses')
mdl.parameters.threads=1
nbbus40 = mdl.integer_var(name='nbBus40')
nbbus30 = mdl.integer_var(name='nbBus30')
mdl.add_constraint(nbbus40*40 + nbbus30*30 >= 300, 'kids')
mdl.minimize(nbbus40*500 + nbbus30*400)
mdl.solve()
print("threads = ",mdl.parameters.threads.get())
for v in mdl.iter_integer_vars():
print(v," = ",v.solution_value)
where I changed
https://github.com/AlexFleischerParis/zoodocplex/blob/master/zoosettings.py
to show how to set the treads parameter
Related
So I have the following code for running skopt.forest_minimize(), but the biggest challenge I am facing right now is that it is taking upwards of days to finish running even just 2 iterations.
SPACE = [skopt.space.Integer(4, max_neighbour, name='n_neighbors', prior='log-uniform'),
skopt.space.Integer(6, 10, name='nr_cubes', prior='uniform'),
skopt.space.Categorical(overlap_cat, name='overlap_perc')]
#skopt.utils.use_named_args(SPACE)
def objective(**params):
score, scomp = tune_clustering(X_cont=X_cont, df=df, pl_brewer=pl_brewer, **params)
if score == 0:
print('saving new scomp')
with open(scomp_file, 'w') as filehandle:
json.dump(scomp, filehandle, default = json_default)
return score
results = skopt.forest_minimize(objective, SPACE, n_calls=1, n_initial_points=1, callback=[scoring])
Is it possible to optimize the following code so that it can compute faster? I noticed that it was barely making use of my CPU, highest CPU utilized is about 30% (it's i7 9th gen with
8 cores).
Also a question while I'm at it, is it possible to utilize a GPU for these computational tasks? I have a 3050 that I can use.
We are using natural nodejs library to classify our users queries in the following way:
const natural = require("natural");
const cls = new natural.LogisticRegressionClassifier();
cls.addDocument("book", "stationary");
cls.addDocument("pen", "stationary");
...
.....
....
5000 + data points
cls.addDocument("last one", "last one");
cls.train(); ----- But This gives heap error and the program crashes.
pino.info("StockNames training successfully completed.");
The train() functions works fine when dataset size is under few hundreds but throwing heap errors and crashing when dataset size is in few thousands. Any suggestions please help. Thanks
So I've got a fairly large optimization problem and I'm trying to solve it within a sensible amount of time.
Ive set it up as:
import pulp as pl
my_problem = LpProblem("My problem",LpMinimize)
# write to problem file
my_problem.writeLP("MyProblem.lp")
And then alternatively
solver = CPLEX_CMD(timeLimit=1, gapRel=0.1)
status = my_problem .solve(solver)
solver = pl.apis.CPLEX_CMD(timeLimit=1, gapRel=0.1)
status = my_problem .solve(solver)
path_to_cplex = r'C:\Program Files\IBM\ILOG\CPLEX_Studio1210\cplex\bin\x64_win64\cplex.exe' # and yes this is the actual path on my machine
solver = pl.apis.cplex_api.CPLEX_CMD(timeLimit=1, gapRel=0.1, path=path_to_cplex)
status = my_problem .solve(solver)
solver = pl.apis.cplex_api.CPLEX_CMD(timeLimit=1, gapRel=0.1, path=path_to_cplex)
status = my_problem .solve(solver)
It runs in each case.
However, the solver does not repond to the timeLimit or gapRel instructions.
If I use timelimit it does warn this is depreciated for timeLimit. Same for fracgap: it tells me I should use relGap. So somehow I am talking to the solver.
However, nor matter what values i pick for timeLimit and relGap, it always returns the exact same answer and takes the exact same amount of time (several minutes).
Also, I have tried alternative solvers, and I cannot get any one of them to accept their variants of time limits or optimization gaps.
In each case, the problem solves and returns an status: optimal message. But it just ignores the time limit and gap instructions.
Any ideas?
out of the zoo example:
import pulp
import cplex
bus_problem = pulp.LpProblem("bus", pulp.LpMinimize)
nbBus40 = pulp.LpVariable('nbBus40', lowBound=0, cat='Integer')
nbBus30 = pulp.LpVariable('nbBus30', lowBound=0, cat='Integer')
# Objective function
bus_problem += 500 * nbBus40 + 400 * nbBus30, "cost"
# Constraints
bus_problem += 40 * nbBus40 + 30 * nbBus30 >= 300
solver = pulp.CPLEX_CMD(options=['set timelimit 40'])
bus_problem.solve(solver)
print(pulp.LpStatus[bus_problem.status])
for variable in bus_problem.variables():
print ("{} = {}".format(variable.name, variable.varValue))
Correct way to pass solver option as dictionary
pulp.CPLEX_CMD(options={'timelimit': 40})
#Alex Fleisher has it correct with pulp.CPLEX_CMD(options=['set timelimit 40']). This also works for CBC using the following syntax:
prob.solve(COIN_CMD(options=['sec 60','Presolve More','Multiple 15', 'Node DownFewest','HEUR on', 'Round On','PreProcess Aggregate','PassP 10','PassF 40','Strong 10','Cuts On', 'Gomory On', 'CutD -1', 'Branch On', 'Idiot -1', 'sprint -1','Reduce On','Two On'],msg=True)).
It is important to understand that the parameters, and associated options, are specific to a solver. PuLP seems to be calling CBC via the command line so an investigation of those things is required. Hope that helps
I am new to TensorFlow. Currently, I am trying to evaluate the performance of distributed TensorFlow using Inception model provided by TensorFlow team.
The thing I want is to generate timestamps for some critical operations in a Parameter Server - Worker architecture, so I can measure the bottleneck (the network lag due to parameter transfer/synchronization or parameter computation cost) on replicas for one iteration (batch).
I came up with the idea of adding a customized dummy py_func operator designated of printing timestamps inside inception_distributed_train.py, with some control dependencies. Here are some pieces of code that I added:
def timer(s):
print ("-------- thread ID ", threading.current_thread().ident, ", ---- Process ID ----- ", getpid(), " ~~~~~~~~~~~~~~~ ", s, datetime.fromtimestamp(time.time()).strftime('%Y-%m-%d %H:%M:%S.%f'))
return Falsedf
dummy1 = tf.py_func(timer, ["got gradients, before dequeues token "], tf.bool)
dummy2 = tf.py_func(timer, ["finished dequeueing the token "], tf.bool)
I modified
apply_gradients_op = opt.apply_gradients(grads, global_step=global_step)
with tf.control_dependencies([apply_gradients_op]):
train_op = tf.identity(total_loss, name='train_op')
into
with tf.control_dependencies([dummy1]):
apply_gradients_op = opt.apply_gradients(grads, global_step=global_step)
with tf.control_dependencies([apply_gradients_op]):
with tf.control_dependencies([dummy2]):
train_op = tf.identity(total_loss, name='train_op')
hoping to print the timestamps before evaluating the apply_gradient_op and after finishing evaluating the apply_gradient_op by enforcing node dependencies.
I did similar things inside sync_replicas_optimizer.apply_gradients, by adding two dummy print nodes before and after update_op:
dummy1 = py_func(timer, ["---------- before update_op "], tf_bool)
dummy2 = py_func(timer, ["---------- finished update_op "], tf_bool)
# sync_op will be assigned to the same device as the global step.
with ops.device(global_step.device), ops.name_scope(""):
with ops.control_dependencies([dummy1]):
update_op = self._opt.apply_gradients(aggregated_grads_and_vars, global_step)
# Clear all the gradients queues in case there are stale gradients.
clear_queue_ops = []
with ops.control_dependencies([update_op]):
with ops.control_dependencies([dummy2]):
for queue, dev in self._one_element_queue_list:
with ops.device(dev):
stale_grads = queue.dequeue_many(queue.size())
clear_queue_ops.append(stale_grads)
I understand that apply_gradient_op is the train_op returned by sync_replicas_optimizer.apply_gradient. And apply_gradient_op is the op to dequeue a token (global_step) from sync_queue managed by the chief worker using chief_queue_runner, so that replica can exit current batch and start a new batch.
In theory, apply_gradient_op should take some time as replica has to wait before it can dequeue the token (global_step) from sync_queue, but the print result for one replica I got, such as the time differences for executing apply_gradient_op is pretty short (~1/1000 sec) and sometimes the print output is indeterministic (especially for chief worker). Here is a snippet of the output on the workers (I am running 2 workers and 1 PS):
chief worker (worker 0) output
worker 1 output
My questions are:
1) I need to record the time TensorFlow takes to execute an op (such as train_op, apply_gradients_op, compute_gradients_op, etc.)
2) Is this the right direction to go, given my ultimate goal is to record the elapsed time for executing certain operations (such as the difference between the time a replica finishes computing gradients and the time it gets the global_step from sync_token)?
3) If this is not the way it should go, please guide me with some insights about the possible ways I could achieve my ultimate goal.
Thank you so much for reading my long long posts. as I have spent weeks working on this!
When using JAGS, how does one receive output from a model in the format:
Inference for Bugs model at "model.txt", fit using jags,
3 chains, each with 10000 iterations (first 5000 discarded)
n.sims = 15000 iterations saved
mu.vect sd.vect 2.5% 25% 50% 75% 97.5% Rhat n.eff
mu 9.950 0.288 9.390 9.755 9.951 10.146 10.505 1.001 11000
sd.obs 3.545 0.228 3.170 3.401 3.534 3.675 3.978 1.001 13000
deviance 820.611 3.460 818.595 819.132 819.961 821.366 825.871 1.001 15000
I assumed, as with BUGS, it would appear when the model completes however I only get something in the format:
Compiling model graph
Resolving undeclared variables
Allocating nodes
Graph information:
Observed stochastic nodes: 1785
Unobserved stochastic nodes: 1843
Total graph size: 61542
Initializing model
|++++++++++++++++++++++++++++++++++++++++++++++++++| 100%
Apologies for the basic question. If anyone can provide useful JAGS introductory material that would also be useful.
Kind regards.
If you only get the 'plus' signs, it means you only initialized the model. When jags really runs, it typically produces '***' signs after. So you are missing a line here (would have been nice to see your code). For instance if you use r2jags, you would write:
out <- jags(data = data, parameters.to.save = params, n.chains = 3, n.iter = 90000,n.burnin = 5000,
model.file = modFile)
out.upd <- update(abundance.out.mod, n.iter=10000)