[
https://issues.apache.org/jira/browse/ARROW-10417?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
]
Shouheng Yi updated ARROW-10417:
--------------------------------
Description:
There might be a memory leak in the {{RecordBatchStreamWriter}}. The memory
resources were not released. It always hit the memory limit and started doing
virtual memory swapping. See the picture below:
!Screen Shot 2020-10-28 at 9.43.32 PM.png!
This was the code:
{code:python}
import tempfile
import os
import sys
import pyarrow as pa
B = 1
KB = 1024 * B
MB = 1024 * KB
schema = pa.schema(
[
pa.field("a_string", pa.string()),
pa.field("an_int", pa.int32()),
pa.field("a_float", pa.float32()),
pa.field("a_list_of_floats", pa.list_(pa.float32())),
]
)
nrows_in_a_batch = 1000
nbatches_in_a_table = 1000
column_arrays = [
["string"] * nrows_in_a_batch,
[123] * nrows_in_a_batch,
[456.789] * nrows_in_a_batch,
[range(1000)] * nrows_in_a_batch,
]
def main(sys_args) -> None:
batch = pa.RecordBatch.from_arrays(column_arrays, schema=schema)
table = pa.Table.from_batches([batch] * nbatches_in_a_table, schema=schema)
with tempfile.TemporaryDirectory() as tmpdir:
filename_template = "file-{n}.arror"
i = 0
while True:
path = os.path.join(tmpdir, filename_template.format(n=i))
i += 1
with pa.OSFile(path, "w") as sink:
with pa.RecordBatchStreamWriter(sink, schema) as writer:
writer.write_table(table)
print(f"pa.total_allocated_bytes():
{pa.total_allocated_bytes() / MB} mb")
if __name__ == "__main__":
main(sys.argv[1:])
{code}
Strangely enough, using {{total_allocated_bytes}}, it seemed normal.
{code:python}
pa.total_allocated_bytes(): 3.95556640625 mb
pa.total_allocated_bytes(): 3.95556640625 mb
pa.total_allocated_bytes(): 3.95556640625 mb
pa.total_allocated_bytes(): 3.95556640625 mb
pa.total_allocated_bytes(): 3.95556640625 mb
{code}
Am I using {{RecordBatchStreamWriter}} incorrectly? If not, how can I release
the resources?
[Updates 10/29/2020]
I changed {{RecordBatchStreamWriter}} to {{RecordBatchFileWriter}} in my code,
i.e.:
{code:python}
...
with pa.OSFile(path, "w") as sink:
with pa.RecordBatchFileWriter(sink, schema) as writer:
writer.write_table(table)
print(f"pa.total_allocated_bytes():
{pa.total_allocated_bytes() / MB} mb")
...
{code}
I observed the same memory profile. I'm wondering if it is caused by
[WriteRecordBatch
|https://github.com/apache/arrow/blob/maint-0.15.x/cpp/src/arrow/ipc/writer.cc#L594]
not being able to release memory.
was:
There might be a memory leak in the {{RecordBatchStreamWriter}}. The memory
resources were not released. It always hit the memory limit and started doing
virtual memory swapping. See the picture below:
!Screen Shot 2020-10-28 at 9.43.32 PM.png!
This was the code:
{code:python}
import tempfile
import os
import sys
import pyarrow as pa
B = 1
KB = 1024 * B
MB = 1024 * KB
schema = pa.schema(
[
pa.field("a_string", pa.string()),
pa.field("an_int", pa.int32()),
pa.field("a_float", pa.float32()),
pa.field("a_list_of_floats", pa.list_(pa.float32())),
]
)
nrows_in_a_batch = 1000
nbatches_in_a_table = 1000
column_arrays = [
["string"] * nrows_in_a_batch,
[123] * nrows_in_a_batch,
[456.789] * nrows_in_a_batch,
[range(1000)] * nrows_in_a_batch,
]
def main(sys_args) -> None:
batch = pa.RecordBatch.from_arrays(column_arrays, schema=schema)
table = pa.Table.from_batches([batch] * nbatches_in_a_table, schema=schema)
with tempfile.TemporaryDirectory() as tmpdir:
filename_template = "file-{n}.arror"
i = 0
while True:
path = os.path.join(tmpdir, filename_template.format(n=i))
i += 1
with pa.OSFile(path, "w") as sink:
with pa.RecordBatchStreamWriter(sink, schema) as writer:
writer.write_table(table)
print(f"pa.total_allocated_bytes():
{pa.total_allocated_bytes() / MB} mb")
if __name__ == "__main__":
main(sys.argv[1:])
{code}
Strangely enough, using {{total_allocated_bytes}}, it seemed normal.
{code:python}
pa.total_allocated_bytes(): 3.95556640625 mb
pa.total_allocated_bytes(): 3.95556640625 mb
pa.total_allocated_bytes(): 3.95556640625 mb
pa.total_allocated_bytes(): 3.95556640625 mb
pa.total_allocated_bytes(): 3.95556640625 mb
{code}
Am I using {{RecordBatchStreamWriter}} incorrectly? If not, how can I release
the resources?
[Updates 10/29/2020]
I changed {{}}
Thank you.
> [Python][C++] Possible Memory Leak in RecordBatchStreamWriter
> -------------------------------------------------------------
>
> Key: ARROW-10417
> URL: https://issues.apache.org/jira/browse/ARROW-10417
> Project: Apache Arrow
> Issue Type: Bug
> Components: C++, Python
> Affects Versions: 0.15.1
> Environment: This is the config for my worker node:
> resources:
> - cpus: 1
> - maxMemoryMb: 4096
> - reservedMemoryMb: 2048
> Reporter: Shouheng Yi
> Priority: Major
> Fix For: 3.0.0, 2.0.1
>
> Attachments: Screen Shot 2020-10-28 at 9.43.32 PM.png, Screen Shot
> 2020-10-28 at 9.43.40 PM.png
>
>
> There might be a memory leak in the {{RecordBatchStreamWriter}}. The memory
> resources were not released. It always hit the memory limit and started doing
> virtual memory swapping. See the picture below:
> !Screen Shot 2020-10-28 at 9.43.32 PM.png!
> This was the code:
> {code:python}
> import tempfile
> import os
> import sys
> import pyarrow as pa
> B = 1
> KB = 1024 * B
> MB = 1024 * KB
> schema = pa.schema(
> [
> pa.field("a_string", pa.string()),
> pa.field("an_int", pa.int32()),
> pa.field("a_float", pa.float32()),
> pa.field("a_list_of_floats", pa.list_(pa.float32())),
> ]
> )
> nrows_in_a_batch = 1000
> nbatches_in_a_table = 1000
> column_arrays = [
> ["string"] * nrows_in_a_batch,
> [123] * nrows_in_a_batch,
> [456.789] * nrows_in_a_batch,
> [range(1000)] * nrows_in_a_batch,
> ]
> def main(sys_args) -> None:
> batch = pa.RecordBatch.from_arrays(column_arrays, schema=schema)
> table = pa.Table.from_batches([batch] * nbatches_in_a_table,
> schema=schema)
> with tempfile.TemporaryDirectory() as tmpdir:
> filename_template = "file-{n}.arror"
> i = 0
> while True:
> path = os.path.join(tmpdir, filename_template.format(n=i))
> i += 1
> with pa.OSFile(path, "w") as sink:
> with pa.RecordBatchStreamWriter(sink, schema) as writer:
> writer.write_table(table)
> print(f"pa.total_allocated_bytes():
> {pa.total_allocated_bytes() / MB} mb")
> if __name__ == "__main__":
> main(sys.argv[1:])
> {code}
> Strangely enough, using {{total_allocated_bytes}}, it seemed normal.
> {code:python}
> pa.total_allocated_bytes(): 3.95556640625 mb
> pa.total_allocated_bytes(): 3.95556640625 mb
> pa.total_allocated_bytes(): 3.95556640625 mb
> pa.total_allocated_bytes(): 3.95556640625 mb
> pa.total_allocated_bytes(): 3.95556640625 mb
> {code}
> Am I using {{RecordBatchStreamWriter}} incorrectly? If not, how can I release
> the resources?
> [Updates 10/29/2020]
> I changed {{RecordBatchStreamWriter}} to {{RecordBatchFileWriter}} in my
> code, i.e.:
> {code:python}
> ...
> with pa.OSFile(path, "w") as sink:
> with pa.RecordBatchFileWriter(sink, schema) as writer:
> writer.write_table(table)
> print(f"pa.total_allocated_bytes():
> {pa.total_allocated_bytes() / MB} mb")
> ...
> {code}
> I observed the same memory profile. I'm wondering if it is caused by
> [WriteRecordBatch
> |https://github.com/apache/arrow/blob/maint-0.15.x/cpp/src/arrow/ipc/writer.cc#L594]
> not being able to release memory.
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