Bug #3726: Enforce Ceph's minimum stripe size in the java bindings - CephFS - Ceph

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Bug #3726

closed

Enforce Ceph's minimum stripe size in the java bindings

Added by Anonymous over 11 years ago. Updated about 5 years ago.

Status:

Resolved

Priority:

Normal

Assignee:

Category:

Target version:

% Done:

Source:

Development

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Backport:

Regression:

Severity:

Reviewed:

Affected Versions:

ceph-qa-suite:

Component(FS):

Hadoop/Java

Labels (FS):

Java/Hadoop

Pull request ID:

Crash signature (v1):

Crash signature (v2):

Description

The Hadoop bindings are using the blocksize as the stripe size. If a block size is explicitly passed down, it ends up being checked by ceph_file_layout_is_valid() in src/include/ceph_fs.cc (eventually). This function requires that the stripe unit be a multiple of 64 K (well, CEPH_MIN_STRIPE_UNIT). We need to adjust the block size in our Hadoop code and then log that we changed the block size on the caller.

Our current plan is to expose CEPH_MIN_STRIPE_UNIT via a JNI call and then do a minimum on that and the specified block size.

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Updated by Anonymous over 11 years ago

After a discussion on jabber, the decision is to go with exposing a function call in libcephfs and then using that in the java bindings. The call will return the #define CEPH_MIN_STRIPE_UNIT for now.

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Updated by Anonymous over 11 years ago

Also, name it something along the lines of get_stripe_granularity() and not .._min(imum)_ as that isn't entirely accurate (the value must be both >= the #define and a multiple of it).

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