Topics

DAOS Object Open Mode

Zhang, Jiafu
 

Hi,

 

I came across this DAOS object open mode enum.  Will you support DAOS_OO_IO_RAND and DAOS_OO_IO_SEQ? How much performance gain we can get for random and sequential access respectively?

 

/** Object open modes */

enum {

              /** Shared read */

              DAOS_OO_RO             = (1 << 1),

              /** Shared read & write, no cache for write */

              DAOS_OO_RW             = (1 << 2),

              /** Exclusive write, data can be cached */

              DAOS_OO_EXCL           = (1 << 3),

              /** unsupported: random I/O */

              DAOS_OO_IO_RAND        = (1 << 4),

              /** unsupported: sequential I/O */

              DAOS_OO_IO_SEQ         = (1 << 5),

};

 

Thanks.

Lombardi, Johann
 

Hi Jiafu,

 

Those flags are placeholders for potential future optimizations (e.g. readahead, client-side aggregation, …) by allowing the application to give us a hint on the expected workload. They are not used currently, so you won’t see any difference if you pass them.

 

Cheers,

Johann

 

From: <daos@daos.groups.io> on behalf of "Zhang, Jiafu" <jiafu.zhang@...>
Reply-To: "daos@daos.groups.io" <daos@daos.groups.io>
Date: Tuesday 9 June 2020 at 03:55
To: "daos@daos.groups.io" <daos@daos.groups.io>
Subject: [daos] DAOS Object Open Mode

 

Hi,

 

I came across this DAOS object open mode enum.  Will you support DAOS_OO_IO_RAND and DAOS_OO_IO_SEQ? How much performance gain we can get for random and sequential access respectively?

 

/** Object open modes */

enum {

              /** Shared read */

              DAOS_OO_RO             = (1 << 1),

              /** Shared read & write, no cache for write */

              DAOS_OO_RW             = (1 << 2),

              /** Exclusive write, data can be cached */

              DAOS_OO_EXCL           = (1 << 3),

              /** unsupported: random I/O */

              DAOS_OO_IO_RAND        = (1 << 4),

              /** unsupported: sequential I/O */

              DAOS_OO_IO_SEQ         = (1 << 5),

};

 

Thanks.

---------------------------------------------------------------------
Intel Corporation SAS (French simplified joint stock company)
Registered headquarters: "Les Montalets"- 2, rue de Paris,
92196 Meudon Cedex, France
Registration Number:  302 456 199 R.C.S. NANTERRE
Capital: 4,572,000 Euros

This e-mail and any attachments may contain confidential material for
the sole use of the intended recipient(s). Any review or distribution
by others is strictly prohibited. If you are not the intended
recipient, please contact the sender and delete all copies.

Zhang, Jiafu
 

Thanks, Johann.

 

From: daos@daos.groups.io <daos@daos.groups.io> On Behalf Of Lombardi, Johann
Sent: Tuesday, June 16, 2020 6:33 PM
To: daos@daos.groups.io
Subject: Re: [daos] DAOS Object Open Mode

 

Hi Jiafu,

 

Those flags are placeholders for potential future optimizations (e.g. readahead, client-side aggregation, …) by allowing the application to give us a hint on the expected workload. They are not used currently, so you won’t see any difference if you pass them.

 

Cheers,

Johann

 

From: <daos@daos.groups.io> on behalf of "Zhang, Jiafu" <jiafu.zhang@...>
Reply-To: "daos@daos.groups.io" <daos@daos.groups.io>
Date: Tuesday 9 June 2020 at 03:55
To: "daos@daos.groups.io" <daos@daos.groups.io>
Subject: [daos] DAOS Object Open Mode

 

Hi,

 

I came across this DAOS object open mode enum.  Will you support DAOS_OO_IO_RAND and DAOS_OO_IO_SEQ? How much performance gain we can get for random and sequential access respectively?

 

/** Object open modes */

enum {

              /** Shared read */

              DAOS_OO_RO             = (1 << 1),

              /** Shared read & write, no cache for write */

              DAOS_OO_RW             = (1 << 2),

              /** Exclusive write, data can be cached */

              DAOS_OO_EXCL           = (1 << 3),

              /** unsupported: random I/O */

              DAOS_OO_IO_RAND        = (1 << 4),

              /** unsupported: sequential I/O */

              DAOS_OO_IO_SEQ         = (1 << 5),

};

 

Thanks.

---------------------------------------------------------------------
Intel Corporation SAS (French simplified joint stock company)
Registered headquarters: "Les Montalets"- 2, rue de Paris,
92196 Meudon Cedex, France
Registration Number:  302 456 199 R.C.S. NANTERRE
Capital: 4,572,000 Euros

This e-mail and any attachments may contain confidential material for
the sole use of the intended recipient(s). Any review or distribution
by others is strictly prohibited. If you are not the intended
recipient, please contact the sender and delete all copies.