Observability: pxf_stat_activity and pxf_cancel_backend

[ostinru]

Add pxf_stat_activity

Add pxf_stat_activity to help DBAs find out what happening inside PXF server.

postgres=# select * from pxf_stat_activity ;
-[ RECORD 1 ]-+---------------------------------------------------------
segment_id    | 1
session_id    | 57997
command_count | 8
xid           | 57997-0000000008
operation     | READ_BRIDGE
usename       | gpadmin
server        | ostinru-test
profile       | s3:parquet
schema_name   | public
table_name    | test_blob_read
data_source   | ostinru-test/topics/cuscom.email.created.v1/2026-05-29/*
query_start   | 2026-06-23 16:16:48.318+03
pxf_host      | example.com

Add pxf_cancel_backend and pxf_interrupt_backend

Add pxf_cancel_backend and pxf_interrupt_backend to allow killing running queries.

Update tests

1. Update pxfExtension tests - use testconatiners.
2. Explicitly define extension version. So, there is no need in sql file manipulations.

[ostinru]

Moved test-related code to separate PR #125 in order to keep PR focused.

[ostinru]

I have tests this PR in order to detect any password leakage to pxf_stat_activity:

db2=#  CREATE EXTERNAL TABLE ext_big_table_100gb (...)
  LOCATION (
      'pxf://public.big_table_100gb?PROFILE=Jdbc&JDBC_DRIVER=org.postgresql.Driver&DB_URL=jdbc:postgresql://pg.example.com:5432/db2&USER=ostinru&PASS=SECRET'
  )
  FORMAT 'CUSTOM' (FORMATTER='pxfwritable_import');


postgres=# select * from pxf_stat_activity ;
-[ RECORD 1 ]-+---------------------------------------------------
segment_id    | 0
session_id    | 112562
command_count | 72
xid           | 112562-0000000072
operation     | READ_BRIDGE
usename       | gpadmin
server        | default
profile       | jdbc
schema_name   | public
table_name    | ext_big_table_100gb
data_source   | public.big_table_100gb
query_start   | 2026-07-31 20:01:50.385+03
pxf_host      | gp.example.com

Also, secret in jdbc URL:

pxf://big_table_100gb?PROFILE=Jdbc&JDBC_DRIVER=com.mysql.jdbc.Driver&DB_URL=jdbc:mysql://ostinru:SECRET@mysql.example.com:3306/db1

postgres=# select * from pxf_stat_activity ;
-[ RECORD 1 ]-+---------------------------------------------------
segment_id    | 1
session_id    | 153617
command_count | 16
xid           | 153617-0000000016
operation     | READ_BRIDGE
usename       | gpadmin
server        | default
profile       | jdbc
schema_name   | public
table_name    | ext_mysql_big_table_100gb
data_source   | big_table_100gb
query_start   | 2026-07-31 21:34:39.361+03
pxf_host      | gp.example.com

with S3:

CREATE EXTERNAL TABLE test_blob_read_with_password (...)
  LOCATION (
      'pxf://ostinru/topics/cuscom.email.created.v1/2026-05-29/*?PROFILE=s3:parquet&SERVER=ostinru&accesskey=SECRET&secretkey=SECRET'
  )
  FORMAT 'CUSTOM' (FORMATTER='pxfwritable_import');

postgres=# select * from pxf_stat_activity ;
-[ RECORD 1 ]-+---------------------------------------------------------
segment_id    | 1
session_id    | 153617
command_count | 99
xid           | 153617-0000000099
operation     | READ_BRIDGE
usename       | gpadmin
server        | ostinru
profile       | s3:parquet
schema_name   | public
table_name    | test_blob_read_with_password
data_source   | ostinru/topics/cuscom.email.created.v1/2026-05-29/*
query_start   | 2026-07-31 21:48:03.509+03
pxf_host      | gp.example.com

[ostinru]

pxf_stat_activity works well.
pxf_cancel_backend and pxf_interrupt_backend works. However not as good as you can expect. That's why I don't add all this to public documentation. I'd prefer to accumulate more feedback from our users.