From dbfc7aa4d0d5457bc92e1e66d065c6088d476843 Mon Sep 17 00:00:00 2001
From: Eric Liang <ekl@databricks.com>
Date: Wed, 14 Sep 2016 13:37:35 -0700
Subject: [PATCH] [SPARK-17472] [PYSPARK] Better error message for
serialization failures of large objects in Python
## What changes were proposed in this pull request?
For large objects, pickle does not raise useful error messages. However, we can wrap them to be slightly more user friendly:
Example 1:
```
def run():
import numpy.random as nr
b = nr.bytes(8 * 1000000000)
sc.parallelize(range(1000), 1000).map(lambda x: len(b)).count()
run()
```
Before:
```
error: 'i' format requires -2147483648 <= number <= 2147483647
```
After:
```
pickle.PicklingError: Object too large to serialize: 'i' format requires -2147483648 <= number <= 2147483647
```
Example 2:
```
def run():
import numpy.random as nr
b = sc.broadcast(nr.bytes(8 * 1000000000))
sc.parallelize(range(1000), 1000).map(lambda x: len(b.value)).count()
run()
```
Before:
```
SystemError: error return without exception set
```
After:
```
cPickle.PicklingError: Could not serialize broadcast: SystemError: error return without exception set
```
## How was this patch tested?
Manually tried out these cases
cc davies
Author: Eric Liang <ekl@databricks.com>
Closes #15026 from ericl/spark-17472.
---
python/pyspark/broadcast.py | 11 ++++++++++-
python/pyspark/cloudpickle.py | 10 ++++++++++
2 files changed, 20 insertions(+), 1 deletion(-)
diff --git a/python/pyspark/broadcast.py b/python/pyspark/broadcast.py
index a0b819220e..74dee14207 100644
--- a/python/pyspark/broadcast.py
+++ b/python/pyspark/broadcast.py
@@ -20,6 +20,8 @@ import sys
import gc
from tempfile import NamedTemporaryFile
+from pyspark.cloudpickle import print_exec
+
if sys.version < '3':
import cPickle as pickle
else:
@@ -75,7 +77,14 @@ class Broadcast(object):
self._path = path
def dump(self, value, f):
- pickle.dump(value, f, 2)
+ try:
+ pickle.dump(value, f, 2)
+ except pickle.PickleError:
+ raise
+ except Exception as e:
+ msg = "Could not serialize broadcast: " + e.__class__.__name__ + ": " + e.message
+ print_exec(sys.stderr)
+ raise pickle.PicklingError(msg)
f.close()
return f.name
diff --git a/python/pyspark/cloudpickle.py b/python/pyspark/cloudpickle.py
index 822ae46e45..da2b2f3757 100644
--- a/python/pyspark/cloudpickle.py
+++ b/python/pyspark/cloudpickle.py
@@ -109,6 +109,16 @@ class CloudPickler(Pickler):
if 'recursion' in e.args[0]:
msg = """Could not pickle object as excessively deep recursion required."""
raise pickle.PicklingError(msg)
+ except pickle.PickleError:
+ raise
+ except Exception as e:
+ if "'i' format requires" in e.message:
+ msg = "Object too large to serialize: " + e.message
+ else:
+ msg = "Could not serialize object: " + e.__class__.__name__ + ": " + e.message
+ print_exec(sys.stderr)
+ raise pickle.PicklingError(msg)
+
def save_memoryview(self, obj):
"""Fallback to save_string"""
--
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