Draft: Replica leverage

Ramon Nourequested to merge
rnou/replica into master

We should be able to do an ior and destroy a deamon and continue.

Merge request reports

CMake/gkfs-config-report.txt.in

+0 −1
Changes for CMake/gkfs-config-report.txt.in: 0 added lines, 1 removed line.
Original line number Diff line number Diff line
@@ -47,7 +47,6 @@ GKFS_ENABLE_UNUSED_FUNCTIONS=@GKFS_ENABLE_UNUSED_FUNCTIONS@ 
GKFS_FOLLOW_EXTERNAL_SYMLINKS=@GKFS_FOLLOW_EXTERNAL_SYMLINKS@

GKFS_USE_GUIDED_DISTRIBUTION=@GKFS_USE_GUIDED_DISTRIBUTION@

GKFS_USE_GUIDED_DISTRIBUTION_PATH=@GKFS_USE_GUIDED_DISTRIBUTION_PATH@

GKFS_USE_LEGACY_PATH_RESOLVE=@GKFS_USE_LEGACY_PATH_RESOLVE@



Limits and reporting

--------------------

CMake/gkfs-options.cmake

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Changes for CMake/gkfs-options.cmake: 0 added lines, 7 removed lines.
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@@ -264,13 +264,6 @@ gkfs_define_option( 
    DEFAULT_VALUE ON

)



# use old resolve function

gkfs_define_option(

    GKFS_USE_LEGACY_PATH_RESOLVE

    HELP_TEXT "Use the old implementation of the resolve function"

    DEFAULT_VALUE OFF

)



cmake_dependent_option(GKFS_INSTALL_TESTS "Install GekkoFS self tests" OFF "GKFS_BUILD_TESTS" OFF)

docs/sphinx/users/running.md

+14 −1
Changes for docs/sphinx/users/running.md: 14 added lines, 1 removed line.
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@@ -364,6 +364,19 @@ This is disabled by default. 
#### Replication



The user can enable the data replication feature by setting the replication environment variable:

`LIBGKFS_NUM_REPL=<num repl>`.

`GKFS_NUM_REPL=<num repl>`.

The number of replicas should go from `0` to the `number of servers - 1`. The replication environment variable can be

set up for each client independently.



Simple-hash replication supports mutation when `GKFS_NUM_REPL` is set

consistently for clients and daemons and the new host count is greater than the

replica count.

Random Slicing with replication remains rejected because independent replica

placement is not defined for that strategy.

Migration plans validate copy indices and placement generations before I/O.



For client-local repair recovery, set `LIBGKFS_REPAIR_JOURNAL_PATH` to a writable

journal path. One client process owns a journal at a time. The adjacent `.lock`

sidecar records the owner and a fingerprint of the configured hosts file; do not

share a journal across client processes or reuse it after changing the topology.

Use `LIBGKFS_REPAIR_STATUS_PATH` to publish a client-local repair queue snapshot.
 
 No newline at end of file

examples/gfind/gfind.cpp

+4 −3
Changes for examples/gfind/gfind.cpp: 4 added lines, 3 removed lines.
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/*

  Copyright 2018-2025, Barcelona Supercomputing Center (BSC), Spain

  Copyright 2015-2025, Johannes Gutenberg Universitaet Mainz, Germany

  Copyright 2018-2026, Barcelona Supercomputing Center (BSC), Spain

  Copyright 2015-2026, Johannes Gutenberg Universitaet Mainz, Germany



  This software was partially supported by the

  EC H2020 funded project NEXTGenIO (Project ID: 671951, www.nextgenio.eu).
@@ -31,7 +31,8 @@ 
  GNU General Public License for more details.



  You should have received a copy of the GNU General Public License

  along with GekkoFS.  If not, see <https://www.gnu.org/licenses/>.

  along with GekkoFS.  If not, see

  <https://www.gnu.org/licenses/>.



  SPDX-License-Identifier: GPL-3.0-or-later

*/

examples/gfind/sfind.cpp

+39 −0
Changes for examples/gfind/sfind.cpp: 39 added lines, 0 removed lines.
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/*

  Copyright 2018-2026, Barcelona Supercomputing Center (BSC), Spain

  Copyright 2015-2026, Johannes Gutenberg Universitaet Mainz, Germany



  This software was partially supported by the

  EC H2020 funded project NEXTGenIO (Project ID: 671951, www.nextgenio.eu).



  This software was partially supported by the

  ADA-FS project under the SPPEXA project funded by the DFG.



  This software was partially supported by the

  the European Union’s Horizon 2020 JTI-EuroHPC research and

  innovation programme, by the project ADMIRE (Project ID: 956748,

  admire-eurohpc.eu)



  This project was partially promoted by the Ministry for Digital Transformation

  and the Civil Service, within the framework of the Recovery,

  Transformation and Resilience Plan - Funded by the European Union

  -NextGenerationEU.



  This file is part of GekkoFS.



  GekkoFS is free software: you can redistribute it and/or modify

  it under the terms of the GNU General Public License as published by

  the Free Software Foundation, either version 3 of the License, or

  (at your option) any later version.



  GekkoFS is distributed in the hope that it will be useful,

  but WITHOUT ANY WARRANTY; without even the implied warranty of

  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

  GNU General Public License for more details.



  You should have received a copy of the GNU General Public License

  along with GekkoFS.  If not, see

  <https://www.gnu.org/licenses/>.



  SPDX-License-Identifier: GPL-3.0-or-later

*/



#include <algorithm>

#include <cerrno>

#include <climits>