Elasticsearch has long [supported](https://www.elastic.co/guide/en/elasticsearch/reference/current/docs-index_.html#index-versioning) compare and set (a.k.a optimistic concurrency control) operations using internal document versioning. Sadly that approach is flawed and can sometime do the wrong thing. Here's the relevant excerpt from the resiliency status page:
> When a primary has been partitioned away from the cluster there is a short period of time until it detects this. During that time it will continue indexing writes locally, thereby updating document versions. When it tries to replicate the operation, however, it will discover that it is partitioned away. It won’t acknowledge the write and will wait until the partition is resolved to negotiate with the master on how to proceed. The master will decide to either fail any replicas which failed to index the operations on the primary or tell the primary that it has to step down because a new primary has been chosen in the meantime. Since the old primary has already written documents, clients may already have read from the old primary before it shuts itself down. The version numbers of these reads may not be unique if the new primary has already accepted writes for the same document
We recently [introduced](https://www.elastic.co/guide/en/elasticsearch/reference/6.x/optimistic-concurrency-control.html) a new sequence number based approach that doesn't suffer from this dirty reads problem.
This commit removes support for internal versioning as a concurrency control mechanism in favor of the sequence number approach.
Relates to #1078
Restricted indices (currently only .security-6 and .security) are special
internal indices that require setting the `allow_restricted_indices` flag
on every index permission that covers them. If this flag is `false`
(default) the permission will not cover these and actions against them
will not be authorized.
However, the monitoring APIs were the only exception to this rule.
This exception is herein forfeited and index monitoring privileges have to be
granted explicitly, using the `allow_restricted_indices` flag on the permission,
as is the case for any other index privilege.
MultiSearchRequests issues through `_msearch` now validate all keys
in the metadata section. Previously unknown keys were ignored
while now an exception is thrown.
Closes#35869
This change removes the wrapping of the created field in the put user
response. The created field was added as a top level field in #32332,
while also still being wrapped within the `user` object of the
response. Since the value is available in both formats in 6.x, we can
remove the wrapped version for 7.0.
Resolving wildcards in aliases expression is challenging as we may end
up with no aliases to replace the original expression with, but if we
replace with an empty array that means _all which is quite the opposite.
Now that we support and serialize the original requested aliases,
whenever aliases are replaced we will be able to know what was
initially requested. `MetaData#findAliases` can then be updated to not
return anything in case it gets empty aliases, but the original aliases
were not empty. That means that empty aliases are interpreted as _all
only if they were originally requested that way.
Relates to #31516
Removes support for storing scripts without the usual json around the
script. So You can no longer do:
```
POST _scripts/<templatename>
{
"query": {
"match": {
"title": "{{query_string}}"
}
}
}
```
and must instead do:
```
POST _scripts/<templatename>
{
"script": {
"lang": "mustache",
"source": {
"query": {
"match": {
"title": "{{query_string}}"
}
}
}
}
}
```
This improves error reporting when you attempt to store a script but don't
quite get the syntax right. Before, there was a good chance that we'd
think of it as a "raw" template and just store it. Now we won't do that.
Nice.
Today when an index is created from shrinking or splitting an existing
index, the target index inherits almost none of the source index
settings. This is surprising and a hassle for operators managing such
indices. Given this is the default behavior, we can not simply change
it. Instead, we start by introducing the ability to copy settings. This
flag can be set on the REST API or on the transport layer and it has the
behavior that it copies all settings from the source except non-copyable
settings (a property of a setting introduced in this
change). Additionally, settings on the request will always override.
This change is the first step in our adventure:
- this flag is added here in 7.0.0 and immediately deprecated
- this flag will be backported to 6.4.0 and remain deprecated
- then, we will remove the ability to set this flag to false in 7.0.0
- finally, in 8.0.0 we will remove this flag and the only behavior will
be for settings to be copied
A previous change modified the output of the thread pool info contained
in the nodes info API. This commit adds a note to the migration docs for
this change.
This metric previously existed for backwards compatibility reasons
although the suggest stats were folded into search stats. This metric
was deprecated in 6.3.0 and this commit removes them for 7.0.0.
CRUD: Parsing changes for UpdateRequest (#29293)
Use `ObjectParser` to parse `UpdateRequest` so we reject unknown fields
and drop support for the `_fields` parameter because it was deprecated
in 5.x.
Stardardize underscore requirements in parameters across different type of
requests:
_index, _type, _source, _id keep their underscores
params like version and retry_on_conflict will be without underscores
Throw an error if older versions of parameters are used
BulkRequest, MultiGetRequest, TermVectorcRequest, MoreLikeThisQuery
were changed
Closes#26886
Boaz Leskes
Albert Zaharovits
Lisa Cawley
Julie Tibshirani
Jason Tedor
Simon Willnauer
lipsill
Jay Modi
Luca Cavanna
Sohaib Iftikhar
Ke Li
joadha
Mayya Sharipova