我有一些代码可以遍历数据库实体,并在任务中运行 - 见下文。
在应用程序引擎上我收到Exceeded soft private memory limit
错误,并且确实检查memory_usage().current()
确认了问题。有关日志记录语句的输出,请参见下文。似乎每次获取一批 foos 时,内存都会增加。
我的问题是:为什么内存没有被垃圾收集?我希望,在循环(分别为循环while
和循环)的每次迭代中,for
名称foos
和变得不可访问),因此有资格进行垃圾收集,然后在内存紧张时进行垃圾收集。但显然它没有发生。foo
foos
foo
from google.appengine.api.runtime import memory_usage
batch_size = 10
dict_of_results = {}
results = 0
cursor = None
while True:
foos = models.Foo.all().filter('status =', 6)
if cursor:
foos.with_cursor(cursor)
for foo in foos.run(batch_size = batch_size):
logging.debug('on result #{} used memory of {}'.format(results, memory_usage().current()))
results +=1
bar = some_module.get_bar(foo)
if bar:
try:
dict_of_results[bar.baz] += 1
except KeyError:
dict_of_results[bar.baz] = 1
if results >= batch_size:
cursor = foos.cursor()
break
else:
break
在 some_module.py
def get_bar(foo):
for bar in foo.bars:
if bar.status == 10:
return bar
return None
logging.debug 的输出(缩短)
on result #1 used memory of 43
on result #2 used memory of 43
.....
on result #20 used memory of 43
on result #21 used memory of 49
.....
on result #32 used memory of 49
on result #33 used memory of 54
.....
on result #44 used memory of 54
on result #45 used memory of 59
.....
on result #55 used memory of 59
.....
.....
.....
on result #597 used memory of 284.3
Exceeded soft private memory limit of 256 MB with 313 MB after servicing 1 requests total