Enable zend observer by default for PHP 8+

Author: jmjoy

docs/en/configuration/ini-settings.md

@@ -19,7 +19,7 @@ This is the configuration list supported in `php.ini`.
 | skywalking_agent.ssl_cert_chain_path             | The certificate file. Enable mTLS when `ssl_key_path` and `ssl_cert_chain_path` exist. Only available when `reporter_type` is `grpc`.                                                                                                             |                           |
 | skywalking_agent.heartbeat_period                | Agent heartbeat report period. Unit, second.                                                                                                                                                                                                      | 30                        |
 | skywalking_agent.properties_report_period_factor | The agent sends the instance properties to the backend every heartbeat_period * properties_report_period_factor seconds.                                                                                                                          | 10                        |
-| skywalking_agent.enable_zend_observer            | Whether to use `zend observer` instead of `zend_execute_ex` to hook the functions, this feature is only available for PHP8+.                                                                                                                      | Off                       |
+| skywalking_agent.enable_zend_observer            | Whether to use `zend observer` instead of `zend_execute_ex` to hook the functions, this feature is only available for PHP8+.                                                                                                                      | On                        |
 | skywalking_agent.reporter_type                   | Reporter type, optional values are `grpc`, `kafka` and `standalone`.                                                                                                                                                                              | grpc                      |
 | skywalking_agent.kafka_bootstrap_servers         | A list of host/port pairs to use for connect to the Kafka cluster. Only available when `reporter_type` is `kafka`.                                                                                                                                |                           |
 | skywalking_agent.kafka_producer_config           | Configure Kafka Producer configuration in JSON format `{"key": "value}`. Only available when `reporter_type` is `kafka`.                                                                                                                          | {}                        |

docs/en/configuration/zend-observer.md

@@ -2,7 +2,7 @@
 
 > Refer to: <https://www.datadoghq.com/blog/engineering/php-8-observability-baked-right-in/#the-observability-landscape-before-php-8>
 
-By default, skywalking-php hooks the `zend_execute_internal` and `zend_execute_ex` functions to implement auto instrumentation.
+On PHP 7, skywalking-php hooks the `zend_execute_internal` and `zend_execute_ex` functions to implement auto instrumentation.
 
 But there are some drawbacks:
 
@@ -28,5 +28,6 @@ opcache.jit = tracing
 [skywalking_agent]
 extension = skywalking_agent.so
 ; Switch to use zend observer api to implement auto instrumentation.
+; Default is On for PHP 8+.
 skywalking_agent.enable_zend_observer = On
 ```

src/lib.rs

@@ -187,7 +187,7 @@ pub fn get_module() -> Module {
         10i64,
         Policy::System,
     );
-    module.add_ini(SKYWALKING_AGENT_ENABLE_ZEND_OBSERVER, false, Policy::System);
+    module.add_ini(SKYWALKING_AGENT_ENABLE_ZEND_OBSERVER, true, Policy::System);
     module.add_ini(
         SKYWALKING_AGENT_REPORTER_TYPE,
         "grpc".to_string(),

tests/common/mod.rs

@@ -70,7 +70,7 @@ pub const EXT: &str = if cfg!(target_os = "linux") {
 };
 
 pub static ENABLE_ZEND_OBSERVER: Lazy<String> =
-    Lazy::new(|| env::var("ENABLE_ZEND_OBSERVER").unwrap_or_else(|_| "Off".to_owned()));
+    Lazy::new(|| env::var("ENABLE_ZEND_OBSERVER").unwrap_or_else(|_| "On".to_owned()));
 
 pub static HTTP_CLIENT: Lazy<reqwest::Client> = Lazy::new(reqwest::Client::new);