#5902
This CL mainly changes:
1. Support setting tags for BE nodes:
```
alter system add backend "1272:9050, 1212:9050" properties("tag.location": "zoneA");
alter system modify backend "1272:9050, 1212:9050" set ("tag.location": "zoneB");
```
And for compatibility, all BE nodes will be set a "default" tag when upgrading: `"tag.location": "default"`.
2. Create a new class `ReplicaAllocation` to replace the previous `replication_num`.
`ReplicaAllocation` represents the allocation of the replicas of a tablet. It contains a map from
Tag to number of replicas.
For example, if user set a table's replication num to 3, it will be converted to a ReplicaAllocation
like: `"tag.location.default" : "3"`, which means the tablet will have 3 replicas and all of them will be
allocated in BE nodes with tag "default";
3. Support create table with replication allocation:
```
CREATE TABLE example_db.table_hash
(
k1 TINYINT
)
DISTRIBUTED BY HASH(k1) BUCKETS 32
PROPERTIES (
"replication_allocation"="tag.location.zone1:1, tag.location.zone2:2"
);
```
Also support set replica allocation for dynamic tables, and modify replica allocation at runtime.
For compatibility, user can still set "replication_num" = "3", and it will be automatically converted to:
` "replication_allocation"="tag.location.default:3"`
4. Support tablet repair and balance based on Tag
1. For tablets of non-colocate table, most of the logic is the same as before,
but when selecting the destination node for clone, the tag of the node will be considered.
If the required tag does not exist, it cannot be repaired.
Similarly, under the condition of ensuring that the replicas are complete, the tablet will be
reallocated according to the tag or the replicas will be balanced.
Balancing is performed separately within each resource group.
2. For tablets of colocate table, the backends sequence of buckets will be splitted by tag.
For example, if replica allocation is "tag.location.zone1:1, tag.location.zone2:2",
And zone1 has 2 BE: A, B; zone2 has 3 BE: C, D, F
there will be 2 backend sequences: one is for zone1, and the other is for zone2.
And one posible seqeunces will be:
zone1: [A] [B] [A] [B]
zone2: [C, D][D, F][F, C][C, D]
5. Support setting tags for user and restrict execution node with tags:
```
set property for 'cmy' 'resource_tags.location' : 'zone1, zone2';
```
After setting, the user 'cmy' can only query data stored on backends with tag zone1 and zone2,
And query can only be executed on backends with tag zone1 and zone2
For compatibility, after upgrading, the property `resource_tags.location` will be empty,
so that user can still query data stored on any backends.
6. Modify the Unit test frame of FE so that we can created multi backends with different mocked IP in unit test.
This help us to easily test some distributed cases like query, tablet repair and balance
The document will be added in another PR.
Also fix a bug described in #6194
# fe-common
This module is used to store some common classes of other modules.
# spark-dpp
This module is Spark DPP program, used for Spark Load function.
Depends: fe-common
# fe-core
This module is the main process module of FE.
Depends: fe-common, spark-dpp
7db8841ae2