glusterfs.git/libglusterfs/src/gfdb/gfdb_data_store.h, branch v3.7.5

tier/ctr: Solving DB Lock issue due to write contention from db connections

2015-09-11T20:46:50+00:00

This is a backport of 12031.

> Problem: The DB on the brick is been accessed by CTR, for write and
> tier migrator, for read and write. The write from tier migrator is reseting
> the heat counters after a cycle. Since we are using sqlite, two connections
> trying to write would cause a db lock contention. As a result CTR used to fail
> to update the db.

> Solution: Using the same db connection of CTR for reseting the heat counters.
> 1) Introducted a new IPC FOP for CTR
> 2) After the query do a ipc syncop to the underlying client xlator associated
>    to the brick.
> 3) CTR in brick will catch the IPC FOP and cleat the heat counters.

> Change-Id: I53306bfc08dcdba479deb4ccc154896521336150
> BUG: 1260730
> Signed-off-by: Joseph Fernandes 
> Reviewed-on: http://review.gluster.org/12031
> Tested-by: NetBSD Build System 
> Tested-by: Gluster Build System 

Signed-off-by: Dan Lambright 

Conflicts:
	xlators/cluster/dht/src/tier.c

Change-Id: I88aa289cdf21e216b42c3d8ccfb4e7e828b43772
BUG: 1262341
Reviewed-on: http://review.gluster.org/12161
Reviewed-by: Joseph Fernandes
Tested-by: NetBSD Build System 
Tested-by: Gluster Build System 
Tested-by: Dan Lambright

cluster/dht: fix tier.c problems found prior to feature freeze

2015-04-06T09:35:37+00:00

This patch resolves tiering translator issues taken from the list
in bug 1203776. These issues have been selected to be fixed
first. The rest will be fixed in a subsequent patch (or are not a
problem).

3. Replace hardcoded #defines of promote/demote file names

6. Use loc_wipe() in migrate_using_query_file()

9. Only promote/demote files on the same node on which they reside.

14. Replace calloc with GF_CALLOC in tier.c and ensure freeing done
properly.

15. Handle if parse_query_str fails

22. Only load gfdb library on server side, remove SQL references
    from client.

Change-Id: I6563b11e58ab2e4c6b1ce44db755781ad6d930fb
BUG: 1203776
Signed-off-by: Dan Lambright 
Reviewed-on: http://review.gluster.org/9987
Tested-by: Gluster Build System 
Reviewed-by: N Balachandran 
Reviewed-by: Niels de Vos

cluster/dht: Add tier translator.

2015-03-21T16:50:29+00:00

The tier translator shares most of DHT's code. It differs in how
subvolumes are chosen for I/Os, and how file migration (cache promotion
and demotion) is managed. That different functionality is split to either
DHT or tier logic according to the "tier_methods" structure.

A cache promotion and demotion thread is created in a manner
similar to the rebalance daemon. The thread operates a timing
wheel which periodically checks for promotion and demotion candidates
(files). Candidates are queued and then migrated. Candidates must exist on
the same node as the daemon and meet other critera per caching policies.

This patch has two authors (Dan Lambright and Joseph Fernandes). Dan
did the DHT changes and Joe wrote the cache policies. The fix depends on
DHT readidr changes and the database library which have been submitted
separately.  Header files in libglusterfs/src/gfdb should be reviewed in
patch 9683.

For more background and design see the feature page [1].

[1]
http://www.gluster.org/community/documentation/index.php/Features/data-classification

Change-Id: Icc26c517ccecf5c42aef039f5b9c6f7afe83e46c
BUG: 1194753
Signed-off-by: Dan Lambright 
Reviewed-on: http://review.gluster.org/9724
Reviewed-by: Vijay Bellur 
Tested-by: Vijay Bellur

Adding Libgfdb to GlusterFS

2015-03-18T17:36:42+00:00

*************************************************************************
			Libgfdb						|
*************************************************************************
Libgfdb provides abstract mechanism to record extra/rich metadata
required for data maintenance, such as data tiering/classification.
It provides consumer with API for recording and querying, keeping
the consumer abstracted from the data store used beneath for storing data.
It works in a plug-and-play model, where data stores can be plugged-in.
Presently we have plugin for Sqlite3. In the future will provide recording
and querying performance optimizer. In the current implementation the schema
of metadata is fixed.

Schema:
~~~~~~
      GF_FILE_TB Table:
      ~~~~~~~~~~~~~~~~~
      This table has one entry per file inode. It holds the metadata required to
      make decisions in data maintenance.
      GF_ID (Primary key)	: File GFID (Universal Unique IDentifier in the namespace)
      W_SEC, W_MSEC 		: Write wind time in sec & micro-sec
      UW_SEC, UW_MSEC		: Write un-wind time in sec & micro-sec
      W_READ_SEC, W_READ_MSEC 	: Read wind time in sec & micro-sec
      UW_READ_SEC, UW_READ_MSEC : Read un-wind time in sec & micro-sec
      WRITE_FREQ_CNTR INTEGER	: Write Frequency Counter
      READ_FREQ_CNTR INTEGER	: Read Frequency Counter

      GF_FLINK_TABLE:
      ~~~~~~~~~~~~~~
      This table has all the hardlinks to a file inode.
      GF_ID		: File GFID               (Composite Primary Key)``|
      GF_PID		: Parent Directory GFID  (Composite Primary Key)   |-> Primary Key
      FNAME 		: File Base Name          (Composite Primary Key)__|
      FPATH 		: File Full Path (Its redundant for now, this will go)
      W_DEL_FLAG 	: This Flag is used for crash consistancy, when a link is unlinked.
                  	  i.e Set to 1 during unlink wind and during unwind this record
                          is deleted
      LINK_UPDATE 	: This Flag is used when a link is changed i.e rename.
                          Set to 1 when rename wind and set to 0 in rename unwind

Libgfdb API:
~~~~~~~~~~~
Refer libglusterfs/src/gfdb/gfdb_data_store.h

Change-Id: I2e9fbab3878ce630a7f41221ef61017dc43db11f
BUG: 1194753
Signed-off-by: Joseph Fernandes 
Signed-off-by: Dan Lambright 
Signed-off-by: Joseph Fernandes 
Reviewed-on: http://review.gluster.org/9683
Tested-by: Gluster Build System 
Reviewed-by: Vijay Bellur