Re: [PATCH v3 4/4] migration: Deprecate old compression method

Signed-off-by: Juan Quintela <quintela(a)redhat.com&gt; Acked-by: Peter Xu <peterx(a)redhat.com&gt; --- docs/about/deprecated.rst | 8 +++ qapi/migration.json | 102 ++++++++++++++++++++++++-------------- migration/options.c | 13 +++++ 3 files changed, 86 insertions(+), 37 deletions(-) diff --git a/docs/about/deprecated.rst b/docs/about/deprecated.rst index e46f3df376..b92621996f 100644 --- a/docs/about/deprecated.rst +++ b/docs/about/deprecated.rst @@ -441,3 +441,11 @@ Please see "QMP invocation for live storage migration with ``driver-mirror`` + NBD" in docs/interop/live-block-operations.rst for a detailed explanation. +old compression method (since 8.2) +'''''''''''''''''''''''''''''''''' + +Compression method fails too much. Too many races. We are going to +remove it if nobody fixes it. For starters, migration-test +compression tests are disabled becase they fail randomly. If you need +compression, use multifd compression methods. + diff --git a/qapi/migration.json b/qapi/migration.json index bf6e1ac5b5..549306fa76 100644 --- a/qapi/migration.json +++ b/qapi/migration.json @@ -243,7 +243,9 @@ # # @compression: migration compression statistics, only returned if # compression feature is on and status is 'active' or 'completed' -# (Since 3.1) +# This feature is unreliable and not tested. It is recommended to +# use multifd migration instead, which offers an alternative +# reliable and tested compression implementation. (Since 3.1) # # @socket-address: Only used for tcp, to know what the real port is # (Since 4.0) @@ -271,8 +273,11 @@ # # Features: # -# @deprecated: @disk migration is deprecated. Use driver-mirror -# with NBD instead. +# @deprecated: @disk migration is deprecated. Use driver-mirror with +# NBD instead. @compression is unreliable and untested. It is +# recommended to use multifd migration, which offers an +# alternative compression implementation that is reliable and +# tested.

# # Since: 0.14 ## @@ -290,7 +295,7 @@ '*blocked-reasons': ['str'], '*postcopy-blocktime': 'uint32', '*postcopy-vcpu-blocktime': ['uint32'], - '*compression': 'CompressionStats', + '*compression': { 'type': 'CompressionStats', 'features': ['deprecated'] }, '*socket-address': ['SocketAddress'], '*dirty-limit-throttle-time-per-round': 'uint64', '*dirty-limit-ring-full-time': 'uint64'} } @@ -445,7 +450,8 @@ # compress and xbzrle are both on, compress only takes effect in # the ram bulk stage, after that, it will be disabled and only # xbzrle takes effect, this can help to minimize migration -# traffic. The feature is disabled by default. (since 2.4 ) +# traffic. The feature is disabled by default. Obsolete. Use

+# multifd compression methods if needed. (since 2.4 ) # # @events: generate events for each migration state change (since 2.4 # )