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Posted to user@hadoop.apache.org by Mikhail Pryakhin <m....@gmail.com> on 2018/08/21 21:39:55 UTC
SFTPConnectionPool connections leakage
Hi,
I’ve come across a connection leakage while using SFTPFileSystem. Methods of SFTPFileSystem operate on poolable ChannelSftp instances, thus some methods of SFTPFileSystem are chained together resulting in establishing multiple connections to the SFTP server to accomplish one compound action, those methods are:
mkdirs method[1]. The public mkdirs method acquires a new ChannelSftp from the pool and then recursively creates directories, checking for the directory existence beforehand by calling the method exists[2] which delegates to the getFileStatus(ChannelSftp channel, Path file) method [3] and so on until it ends up in returning the FilesStatus instance [4]. The resource leakage occurs in the method getWorkingDirectory which calls the getHomeDirectory method [5] which in turn establishes a new connection to the sftp server instead of using an already created connection. As the mkdirs method is recursive this results in creating a huge number of connections.
open method [6]. This method returns an instance of FSDataInputStream which consumes SFTPInputStream instance which doesn't return an acquired ChannelSftp instance back to the pool but instead it closes it[7]. This leads to establishing another connection to an SFTP server when the next method is called on the FileSystem instance.
I’ve issued a Jira ticket https://issues.apache.org/jira/browse/HADOOP-15358 <https://issues.apache.org/jira/browse/HADOOP-15358>, and fixed the connection leakage issue.
Could I create a pull request to merge the fix?
[1] https://github.com/apache/hadoop/blob/736ceab2f58fb9ab5907c5b5110bd44384038e6b/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/fs/sftp/SFTPFileSystem.java#L658
[2] https://github.com/apache/hadoop/blob/736ceab2f58fb9ab5907c5b5110bd44384038e6b/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/fs/sftp/SFTPFileSystem.java#L321
[3] https://github.com/apache/hadoop/blob/736ceab2f58fb9ab5907c5b5110bd44384038e6b/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/fs/sftp/SFTPFileSystem.java#L202
[4] https://github.com/apache/hadoop/blob/736ceab2f58fb9ab5907c5b5110bd44384038e6b/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/fs/sftp/SFTPFileSystem.java#L290
[5] https://github.com/apache/hadoop/blob/736ceab2f58fb9ab5907c5b5110bd44384038e6b/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/fs/sftp/SFTPFileSystem.java#L640
[6] https://github.com/apache/hadoop/blob/736ceab2f58fb9ab5907c5b5110bd44384038e6b/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/fs/sftp/SFTPFileSystem.java#L504
[7] https://github.com/apache/hadoop/blob/736ceab2f58fb9ab5907c5b5110bd44384038e6b/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/fs/sftp/SFTPInputStream.java#L123 <https://github.com/apache/hadoop/blob/736ceab2f58fb9ab5907c5b5110bd44384038e6b/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/fs/sftp/SFTPInputStream.java#L123>
Kind Regards,
Mike Pryakhin
Re: SFTPConnectionPool connections leakage
Posted by Mikhail Pryakhin <m....@gmail.com>.
Hi Aprit,
I contributed the patch[1] long ago, but it hasn’t been merged yet. Could
you please tell when to expect it in the main branch?
[1]
https://issues.apache.org/jira/browse/HADOOP-15358
Cheers,
Mike
On Wed, 22 Aug 2018 at 01:06, Mikhail Pryakhin <m....@gmail.com> wrote:
> Hi Arpit,
> Thank you, will contribute the fix shortly.
>
> On Wed, 22 Aug 2018 at 00:52, Arpit Agarwal <aa...@hortonworks.com>
> wrote:
>
>> Hi Mikhail,
>>
>>
>>
>> There’s two ways to contribute a fix:
>>
>> 1. Attach a patch file to the Jira and click “Submit Patch”. I’ve
>> made you a contributor and assigned it to you.
>> 2. Submit a GitHub pull request with the Jira key in the title. Not
>> tried this in a while and not sure it still works.
>>
>>
>>
>>
>>
>> *From: *Mikhail Pryakhin <m....@gmail.com>
>> *Date: *Tuesday, August 21, 2018 at 2:40 PM
>> *To: *<us...@hadoop.apache.org>
>> *Subject: *SFTPConnectionPool connections leakage
>>
>>
>>
>> Hi,
>>
>> I’ve come across a connection leakage while using SFTPFileSystem. Methods
>> of SFTPFileSystem operate on poolable ChannelSftp instances, thus some
>> methods of SFTPFileSystem are chained together resulting in establishing
>> multiple connections to the SFTP server to accomplish one compound action,
>> those methods are:
>>
>>
>>
>> *mkdirs method*[1]*. *The public mkdirs method acquires a new
>> ChannelSftp from the pool and then recursively creates directories,
>> checking for the directory existence beforehand by calling the method
>> exists[2] which delegates to the getFileStatus(ChannelSftp channel, Path
>> file) method [3] and so on until it ends up in returning the FilesStatus
>> instance [4]. The resource leakage occurs in the method getWorkingDirectory
>> which calls the getHomeDirectory method [5] which in turn establishes a new
>> connection to the sftp server instead of using an already created
>> connection. As the mkdirs method is recursive this results in creating a
>> huge number of connections.
>>
>>
>>
>> *open method* [6]. This method returns an instance of FSDataInputStream
>> which consumes SFTPInputStream instance which doesn't return an acquired
>> ChannelSftp instance back to the pool but instead it closes it[7]. This
>> leads to establishing another connection to an SFTP server when the next
>> method is called on the FileSystem instance.
>>
>>
>>
>> I’ve issued a Jira ticket
>> https://issues.apache.org/jira/browse/HADOOP-15358, and fixed the
>> connection leakage issue.
>>
>> Could I create a pull request to merge the fix?
>>
>>
>>
>> [1]
>> https://github.com/apache/hadoop/blob/736ceab2f58fb9ab5907c5b5110bd44384038e6b/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/fs/sftp/SFTPFileSystem.java#L658
>>
>> [2]
>> https://github.com/apache/hadoop/blob/736ceab2f58fb9ab5907c5b5110bd44384038e6b/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/fs/sftp/SFTPFileSystem.java#L321
>>
>> [3]
>> https://github.com/apache/hadoop/blob/736ceab2f58fb9ab5907c5b5110bd44384038e6b/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/fs/sftp/SFTPFileSystem.java#L202
>>
>> [4]
>> https://github.com/apache/hadoop/blob/736ceab2f58fb9ab5907c5b5110bd44384038e6b/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/fs/sftp/SFTPFileSystem.java#L290
>>
>> [5]
>> https://github.com/apache/hadoop/blob/736ceab2f58fb9ab5907c5b5110bd44384038e6b/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/fs/sftp/SFTPFileSystem.java#L640
>>
>> [6]
>> https://github.com/apache/hadoop/blob/736ceab2f58fb9ab5907c5b5110bd44384038e6b/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/fs/sftp/SFTPFileSystem.java#L504
>>
>> [7]
>> https://github.com/apache/hadoop/blob/736ceab2f58fb9ab5907c5b5110bd44384038e6b/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/fs/sftp/SFTPInputStream.java#L123
>>
>>
>>
>>
>>
>> Kind Regards,
>>
>> Mike Pryakhin
>>
>>
>>
>> --
> Regards, Mikhail Pryakhin.
>
--
Regards, Mikhail Pryakhin.
Re: SFTPConnectionPool connections leakage
Posted by Mikhail Pryakhin <m....@gmail.com>.
Hi Arpit,
Thank you, will contribute the fix shortly.
On Wed, 22 Aug 2018 at 00:52, Arpit Agarwal <aa...@hortonworks.com>
wrote:
> Hi Mikhail,
>
>
>
> There’s two ways to contribute a fix:
>
> 1. Attach a patch file to the Jira and click “Submit Patch”. I’ve made
> you a contributor and assigned it to you.
> 2. Submit a GitHub pull request with the Jira key in the title. Not
> tried this in a while and not sure it still works.
>
>
>
>
>
> *From: *Mikhail Pryakhin <m....@gmail.com>
> *Date: *Tuesday, August 21, 2018 at 2:40 PM
> *To: *<us...@hadoop.apache.org>
> *Subject: *SFTPConnectionPool connections leakage
>
>
>
> Hi,
>
> I’ve come across a connection leakage while using SFTPFileSystem. Methods
> of SFTPFileSystem operate on poolable ChannelSftp instances, thus some
> methods of SFTPFileSystem are chained together resulting in establishing
> multiple connections to the SFTP server to accomplish one compound action,
> those methods are:
>
>
>
> *mkdirs method*[1]*. *The public mkdirs method acquires a new ChannelSftp
> from the pool and then recursively creates directories, checking for the
> directory existence beforehand by calling the method exists[2] which
> delegates to the getFileStatus(ChannelSftp channel, Path file) method [3]
> and so on until it ends up in returning the FilesStatus instance [4]. The
> resource leakage occurs in the method getWorkingDirectory which calls the
> getHomeDirectory method [5] which in turn establishes a new connection to
> the sftp server instead of using an already created connection. As the
> mkdirs method is recursive this results in creating a huge number of
> connections.
>
>
>
> *open method* [6]. This method returns an instance of FSDataInputStream
> which consumes SFTPInputStream instance which doesn't return an acquired
> ChannelSftp instance back to the pool but instead it closes it[7]. This
> leads to establishing another connection to an SFTP server when the next
> method is called on the FileSystem instance.
>
>
>
> I’ve issued a Jira ticket
> https://issues.apache.org/jira/browse/HADOOP-15358, and fixed the
> connection leakage issue.
>
> Could I create a pull request to merge the fix?
>
>
>
> [1]
> https://github.com/apache/hadoop/blob/736ceab2f58fb9ab5907c5b5110bd44384038e6b/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/fs/sftp/SFTPFileSystem.java#L658
>
> [2]
> https://github.com/apache/hadoop/blob/736ceab2f58fb9ab5907c5b5110bd44384038e6b/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/fs/sftp/SFTPFileSystem.java#L321
>
> [3]
> https://github.com/apache/hadoop/blob/736ceab2f58fb9ab5907c5b5110bd44384038e6b/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/fs/sftp/SFTPFileSystem.java#L202
>
> [4]
> https://github.com/apache/hadoop/blob/736ceab2f58fb9ab5907c5b5110bd44384038e6b/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/fs/sftp/SFTPFileSystem.java#L290
>
> [5]
> https://github.com/apache/hadoop/blob/736ceab2f58fb9ab5907c5b5110bd44384038e6b/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/fs/sftp/SFTPFileSystem.java#L640
>
> [6]
> https://github.com/apache/hadoop/blob/736ceab2f58fb9ab5907c5b5110bd44384038e6b/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/fs/sftp/SFTPFileSystem.java#L504
>
> [7]
> https://github.com/apache/hadoop/blob/736ceab2f58fb9ab5907c5b5110bd44384038e6b/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/fs/sftp/SFTPInputStream.java#L123
>
>
>
>
>
> Kind Regards,
>
> Mike Pryakhin
>
>
>
> --
Regards, Mikhail Pryakhin.
Re: SFTPConnectionPool connections leakage
Posted by Arpit Agarwal <aa...@hortonworks.com>.
Hi Mikhail,
There’s two ways to contribute a fix:
1. Attach a patch file to the Jira and click “Submit Patch”. I’ve made you a contributor and assigned it to you.
2. Submit a GitHub pull request with the Jira key in the title. Not tried this in a while and not sure it still works.
From: Mikhail Pryakhin <m....@gmail.com>
Date: Tuesday, August 21, 2018 at 2:40 PM
To: <us...@hadoop.apache.org>
Subject: SFTPConnectionPool connections leakage
Hi,
I’ve come across a connection leakage while using SFTPFileSystem. Methods of SFTPFileSystem operate on poolable ChannelSftp instances, thus some methods of SFTPFileSystem are chained together resulting in establishing multiple connections to the SFTP server to accomplish one compound action, those methods are:
mkdirs method[1]. The public mkdirs method acquires a new ChannelSftp from the pool and then recursively creates directories, checking for the directory existence beforehand by calling the method exists[2] which delegates to the getFileStatus(ChannelSftp channel, Path file) method [3] and so on until it ends up in returning the FilesStatus instance [4]. The resource leakage occurs in the method getWorkingDirectory which calls the getHomeDirectory method [5] which in turn establishes a new connection to the sftp server instead of using an already created connection. As the mkdirs method is recursive this results in creating a huge number of connections.
open method [6]. This method returns an instance of FSDataInputStream which consumes SFTPInputStream instance which doesn't return an acquired ChannelSftp instance back to the pool but instead it closes it[7]. This leads to establishing another connection to an SFTP server when the next method is called on the FileSystem instance.
I’ve issued a Jira ticket https://issues.apache.org/jira/browse/HADOOP-15358, and fixed the connection leakage issue.
Could I create a pull request to merge the fix?
[1] https://github.com/apache/hadoop/blob/736ceab2f58fb9ab5907c5b5110bd44384038e6b/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/fs/sftp/SFTPFileSystem.java#L658
[2] https://github.com/apache/hadoop/blob/736ceab2f58fb9ab5907c5b5110bd44384038e6b/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/fs/sftp/SFTPFileSystem.java#L321
[3] https://github.com/apache/hadoop/blob/736ceab2f58fb9ab5907c5b5110bd44384038e6b/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/fs/sftp/SFTPFileSystem.java#L202
[4] https://github.com/apache/hadoop/blob/736ceab2f58fb9ab5907c5b5110bd44384038e6b/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/fs/sftp/SFTPFileSystem.java#L290
[5] https://github.com/apache/hadoop/blob/736ceab2f58fb9ab5907c5b5110bd44384038e6b/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/fs/sftp/SFTPFileSystem.java#L640
[6] https://github.com/apache/hadoop/blob/736ceab2f58fb9ab5907c5b5110bd44384038e6b/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/fs/sftp/SFTPFileSystem.java#L504
[7] https://github.com/apache/hadoop/blob/736ceab2f58fb9ab5907c5b5110bd44384038e6b/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/fs/sftp/SFTPInputStream.java#L123
Kind Regards,
Mike Pryakhin