[Why]
When node A becomes the leader, it still takes a few exchanges with
followers to allow cluster changes again.
Concurrently, the testcase blocks traffic between A and other nodes to
simulate a network partition. If this happens after A becomes the leader
but before cluster changes are permitted again, the testcase will never
succeed and will eventually abort with:
Case: cluster_minority_SUITE:remove_node_when_seed_node_is_leader
Reason: {error,
{{awaitMatch,
[{module,cluster_minority_SUITE},
{expression, "..."},
{pattern,"ok"},
{value,
{error,69,<<"Error:\ncluster_change_not_permitted">>}}]},
[How]
Before blocking traffic, we wait for cluster changes to be permitted
again on node A.
## What?
This commit displays effective filters of AMQP receivers in the Management UI.
There is a new column `Filters` for outgoing links.
Solves #13429
## Why?
This allows validating if the desired filters set by the receiver are
actually in place by the server.
In addition, it's convenient for a developer to check any filter values
including SQL filter expressions.
## How?
The session process stores the the formatted and effective filters in
its state.
The Management UI displays a box containing the filter name. This way
the table for the outgoing links is kept concise. Hovering with the
mouse over a box will show additionally the descriptor and the actual
filter-value/definition.
A higher priority SAC consumer was never activated when a
quiescing consumer returned or requeued it's last message.
NB: this required a new machine version: 7
Elixir 1.18 comes with a JSON package which leads to errors like this:
```
Duplicate modules: [["/home/runner/work/_temp/.setup-beam/elixir/bin/../lib/elixir/ebin/Elixir.JSON.Encoder.Float.beam",
"/home/runner/work/rabbitmq-server/rabbitmq-server/deps/json/ebin/Elixir.JSON.Encoder.Float.beam"],
```
Test case two_nodes_different_otp_version was introduced in
https://github.com/rabbitmq/rabbitmq-server/pull/14042.
In CI, the code was compiled on OTP 27. The test case then applied the
Ra commands on OTP 27 and OTP 26 at runtime. For that to work the test
transferred the compiled BEAM modules to the OTP 26 node.
Bumping OTP to 28 causes the lower version node (be it OTP 26 or OTP 27)
to error when parsing the atom table chunk of the BEAM file that was
compiled in OTP 28:
```
corrupt atom table
{error,badfile}
```
That's expected as described in https://github.com/erlang/otp/pull/8913#issue-2572291638
since https://github.com/erlang/otp/pull/8913 changes the atom table chunk
format in the BEAM files.
```
beam_lib:chunks("deps/rabbit/ebin/lqueue.beam", [atoms]).
```
will parse successfully if the file gets loaded on OTP 28 irrespective
of whether the file was compiled with OTP 27 or 28.
However, this file fails to load if it is compiled with 28 and loaded on
27.
There is the `no_long_atoms` option that we could use just for this test
case.
However, given that we have a similar test case
two_nodes_same_otp_version we skip test case two_nodes_different_otp_version
in this commit.
Really, the best solution would be to use different OTP versions in
RabbitMQ mixed version testing in addition to using different RabbitMQ
versions. This way, the test case could just RPC into the different
RabbitMQ nodes and apply the Ra commands there.
Without this change delete/3 callback for custom exchange type wasn't called and warning about invalid exchange type appeared in the logs.
What is interesting that exchange module was logged as an invalid type for previously declared exchange of that module ¯\_(ツ)_/¯.
## What?
This commit allows AMQP 1.0 clients to define SQL-like filter expressions when consuming from streams, enabling server-side message filtering.
RabbitMQ will only dispatch messages that match the provided filter expression, reducing network traffic and client-side processing overhead.
SQL filter expressions are a more powerful alternative to the [AMQP Property Filter Expressions](https://www.rabbitmq.com/blog/2024/12/13/amqp-filter-expressions) introduced in RabbitMQ 4.1.
SQL filter expressions are based on the [JMS message selector syntax](https://jakarta.ee/specifications/messaging/3.1/jakarta-messaging-spec-3.1#message-selector-syntax) and support:
* Comparison operators (`=`, `<>`, `>`, `<`, `>=`, `<=`)
* Logical operators (`AND`, `OR`, `NOT`)
* Arithmetic operators (`+`, `-`, `*`, `/`)
* Special operators (`BETWEEN`, `LIKE`, `IN`, `IS NULL`)
* Access to the properties and application-properties sections
**Examples**
Simple expression:
```sql
header.priority > 4
```
Complex expression:
```sql
order_type IN ('premium', 'express') AND
total_amount BETWEEN 100 AND 5000 AND
(customer_region LIKE 'EU-%' OR customer_region = 'US-CA') AND
properties.creation-time >= 1750772279000 AND
NOT cancelled
```
Like AMQP property filter expressions, SQL filter expressions can be
combined with Bloom filters. Combining both allows for highly customisable
expressions (SQL) and extremely fast evaluation (Bloom filter) if only a
subset of the chunks need to be read from disk.
## Why?
Compared to AMQP property filter expressions, SQL filter expressions provide the following advantage:
* High expressiveness and flexibility in defining the filter
Like for AMQP property filter expressions, the following advantages apply:
* No false positives (as is the case for Bloom filters)
* Multiple concurrent clients can attach to the same stream each consuming
only a specific subset of messages while preserving message order.
* Low network overhead as only messages that match the filter are
transferred to the client
* Likewise, lower resource usage (CPU and memory) on clients since they
don't need to deserialise messages that they are not interested in.
* If the SQL expression is simple, even the broker will save resources
because it doesn't need to serialse and send messages that the client
isn't interested in.
## How?
### JMS Message Selector Syntax vs. AMQP Extension Spec
The AMQP Filter Expressions Version 1.0 extension Working Draft 09 defines SQL Filter Expressions in Section 6.
This spec differs from the JMS message selector spec. Neither is a subset of the other. We can choose to follow either.
However, I think it makes most sense to follow the JMS spec because:
* The JMS spec is better defined
* The JMS spec is far more widespread than the AMQP Working Draft spec. (A slight variation of the AMQP Working
Draft is used by Azure Service Bus: https://learn.microsoft.com/en-us/azure/service-bus-messaging/service-bus-messaging-sql-filter)
* The JMS spec is mostly simpler (partly because matching on only simple types)
* This will allow for a single SQL parser in RabbitMQ for both AMQP clients consuming from a stream and possibly in future for JMS clients consuming from queues or topics.
<details>
<summary>AMQP extension spec vs JMS spec</summary>
AMQP
!= is synonym for <>
JMS
defines only <>
Conclusion
<> is sufficient
AMQP
Strings can be tested for “greater than”
“both operands are of type string or of type symbol (any combination is permitted) and
the lexicographical rank of the left operand is greater than the lexicographical rank of the right operand”
JMS
“String and Boolean comparison is restricted to = and <>.”
Conclusion
The JMS behaviour is sufficient.
AMQP
IN <set-expression>
set-expression can contain non-string literals
JMS:
set-expression can contain only string literals
Conclusion
The JMS behaviour is sufficient.
AMQP
EXISTS predicate to check for composite types
JMS
Only simple types
Conclusion
We want to match only for simple types, i.e. allowing matching only against values in the application-properties, properties sections and priority field of the header section.
AMQP:
Modulo operator %
Conclusion
JMS doesn't define the modulo operator. Let's start without it.
We can decide in future to add support since it can actually be useful, for example for two receivers who want to process every other message.
AMQP:
The ‘+’ operator can concatenate string and symbol values
Conclusion
Such string concatenation isn't defined in JMS. We don't need it.
AMQP:
Define NAN and INF
JMS:
“Approximate literals use the Java floating-point literal syntax.”
Examples include "7."
Conclusion
We can go with the JMS spec given that needs to be implemented anyway
for JMS support.
Scientific notations are supported in both the AMQP spec and JMS spec.
AMQP
String literals can be surrounded by single or double quotation marks
JMS
A string literal is enclosed in single quotes
Conclusion
Supporting single quotes is good enough.
AMQP
“A binary constant is a string of pairs of hexadecimal digits prefixed by ‘0x’ that are not enclosed in quotation marks”
Conclusion
JMS doesn't support binary constants. We can start without binary constants.
Matching against binary values are still supported if these binary values can be expressed as UTF-8 strings.
AMQP
Functions DATE, UTC, SUBSTRING, LOWER, UPPER, LEFT, RIGHT
Vendor specific functions
Conclusion
JMS doesn't define such functions. We can start without those functions.
AMQP
<field><array_element_reference>
<field>‘.’<composite_type_reference>
to access map and array elements
Conclusion
Same as above:
We want to match only for simple types, i.e. allowing matching only against values in the application-properties, properties sections and priority field of the header section.
AMQP
allows for delimited identifiers
JMS
Java identifier part characters
Conclusion
We can go with the Java identifiers extending the allowed characters by
`.` and `-` to reference field names such as `properties.group-id`.
JMS:
BETWEEN operator
Conclusion
The BETWEEN operator isn't supported in the AMQP spec. Let's support it as convenience since it's already available in JMS.
</details>
### Filter Name
The client provides a filter with name `sql-filter` instead of name
`jms-selector` to allow to differentiate between JMS clients and other
native AMQP 1.0 clients using SQL expressions. This way, we can also
optionally extend the SQL grammar in future.
### Identifiers
JMS message selectors allow identifiers to contain some well known JMS headers that match to well known AMQP fields, for example:
```erl
jms_header_to_amqp_field_name(<<"JMSDeliveryMode">>) -> durable;
jms_header_to_amqp_field_name(<<"JMSPriority">>) -> priority;
jms_header_to_amqp_field_name(<<"JMSMessageID">>) -> message_id;
jms_header_to_amqp_field_name(<<"JMSTimestamp">>) -> creation_time;
jms_header_to_amqp_field_name(<<"JMSCorrelationID">>) -> correlation_id;
jms_header_to_amqp_field_name(<<"JMSType">>) -> subject;
%% amqp-bindmap-jms-v1.0-wd10 § 3.2.2 JMS-defined ’JMSX’ Properties
jms_header_to_amqp_field_name(<<"JMSXUserID">>) -> user_id;
jms_header_to_amqp_field_name(<<"JMSXGroupID">>) -> group_id;
jms_header_to_amqp_field_name(<<"JMSXGroupSeq">>) -> group_sequence;
```
This commit does a similar matching for `header.` and `properties.` prefixed identifiers to field names in the AMQP property section.
The only field that is supported to filter on in the AMQP header section is `priority`, that is identifier `header.priority`.
By default, as described in the AMQP extension spec, if an identifier is not prefixed, it refers to a key in the application-properties section.
Hence, all identifiers prefixed with `header.`, and `properties.` have special meanings and MUST be avoided by applications unless they want to refer to those specific fields.
Azure Service Bus uses the `sys.` and `user.` prefixes for well known field names and arbitrary application-provided keys, respectively.
### SQL lexer, parser and evaluator
This commit implements the SQL lexer and parser in files rabbit_jms_selector_lexer.xrl and
rabbit_jms_selector_parser.yrl, respectively.
Advantages:
* Both the definitions in the lexer and the grammar in the parser are defined **declaratively**.
* In total, the entire SQL syntax and grammar is defined in only 240 lines.
* Therefore, lexer and parser are simple to maintain.
The idea of this commit is to use the same lexer and parser for native AMQP clients consumings
from streams (this commit) as for JMS clients (in the future).
All native AMQP client vs JMS client bits are then manipulated after
the Abstract Syntax Tree (AST) has been created by the parser.
For example, this commit transforms the AST specifically for native AMQP clients
by mapping `properties.` prefixed identifiers (field names) to atoms.
A JMS client's mapping from `JMS` prefixed headers can transform the AST
differently.
Likewise, this commit transforms the AST to compile a regex for complex LIKE
expressions when consuming from a stream while a future version
might not want to compile a regex when consuming from quorum queues.
Module `rabbit_jms_ast` provides such AST helper methods.
The lexer and parser are not performance critical as this work happens
upon receivers attaching to the stream.
The evaluator however is performance critical as message evaluation
happens on the hot path.
### LIKE expressions
The evaluator has been optimised to only compile a regex when necessary.
If the LIKE expression-value contains no wildcard or only a single `%`
wildcard, Erlang pattern matching is used as it's more efficient.
Since `_` can match any UTF-8 character, a regex will be compiled with
the `[unicode]` options.
### Filter errors
Any errors upon a receiver attaching to a stream causes the filter to
not become active. RabbitMQ will log a warning describing the reason and
will omit the named filter in its attach reply frame. The client lib is
responsible for detaching the link as explained in the AMQP spec:
> The receiving endpoint sets its desired filter, the sending endpoint sets the filter actually in place
(including any filters defaulted at the node). The receiving endpoint MUST check that the filter in
place meets its needs and take responsibility for detaching if it does not.
This applies to lexer and parser errors.
Errors during message evaluation will result in an unknown value.
Conditional operators on unknown are described in the JMS spec. If the
entire selector condition is unknown, the message does not match, and
will therefore not be delivered to the client.
## Clients
Support for passing the SQL expression from app to broker is provided by
the Java client in https://github.com/rabbitmq/rabbitmq-amqp-java-client/pull/216
If a stream or quorum queue has opened a file to read a consumer message
and the queue is deleted the file handle reference is lost and kept
open until the end of the channel lifetime.
Michal Kuratczyk
Michael Klishin
David Ansari
Jean-Sébastien Pédron
dependabot[bot]
Karl Nilsson
Arnaud Cogoluègnes
Iliia Khaprov - VMware by Broadcom
Luke Bakken