Hi Ted,

There shouldn't be a limit to the number of backtests that you can run at once. Out of curiosity, what made you think that you had been shut down? Our database + servers are usually quite busy from about 7-9:30 in the morning. Perhaps that's what you were noticing?

Jamie

Hmm, I keep getting the response in a message panel "Error - There was a problem starting your backtest. Please try again"

The url at the top of the page is:
https://www.quantopian.com/algorithms/57ff86a3b94c99c8b00002e7/new_backtest?s=1

ted

Hah! There was an error in the actual code. I saw the error when I ran the backtest as Ctrl-B rather than clicking on the button for a full backtest. I corrected the error, saved the algo, went back and reloaded the backtest, off and running now. Sorry about that.

Is there a way to put a timer so I can see how long each simulation takes and if I run multiple full backrests, I can see the average simulation time.

For elapsed time at the end of the backtest along with wall clock time which you can change for your timezone anywhere in the world.
Edit: List of time zones

2018-10-04 12:59 at_end:122 INFO Elapsed: 1 hr 3.1 min 2018-10-05 22:29 US/Eastern

import time  
from datetime import datetime as dt  
from pytz     import timezone as tz

def at_end(context, data):  
    if get_datetime().date() != context.end_date:  # only proceed if last day of backtest  
        return

    tzone = 'US/Eastern'  
    elapsed = (time.time() - context.time_start) / 60   # Minutes  
    log.info('Elapsed: {} hr  {} min   {} {}\n'.format(  
        int(elapsed / 60), '%.1f' % (elapsed % 60),  
        dt.now(tz(tzone)).strftime('%Y-%m-%d %H:%M'), tzone))  
    # Elapsed: 1 hr  3.1 min   2018-10-05 22:29 US/Eastern

def initialize(context):  
    context.time_start = time.time()  # seconds since 1970  
    context.end_date   = get_environment('end').date()  
    schedule_function(at_end, date_rules.every_day(), time_rules.market_close())  

Thats amazing. Its working.

May I know how many simulations I can run at one go?

tks