cherry pick pingcap#4997 to master

Signed-off-by: ti-srebot <ti-srebot@pingcap.com>

log-redaction.md

@@ -43,7 +43,11 @@ To enable log redaction in the TiKV side, set the value of [`security.redact-inf
 
 ## Log redaction in PD side
 
+<<<<<<< HEAD
 To enable log redaction in the PD side, set the value of [`security.redact-info-log`](/pd-configuration-file.md#redact-info-log-new-in-v500-rc) to `true`. This configuration value defaults to `false`, which means that log redaction is disabled.
+=======
+To enable log redaction in the PD side, set the value of [`security.redact-info-log`](/pd-configuration-file.md#redact-info-log-new-in-v4010) to `true`. This configuration value defaults to `false`, which means that log redaction is disabled.
+>>>>>>> 5b116f80... Log redact on TiFlash and PD (4.0) (#4997)
 
 ## Log redaction in TiFlash side
 

pd-configuration-file.md

@@ -143,7 +143,11 @@ Configuration items related to security
 + The path of the PEM file that contains the X509 key
 + Default value: ""
 
+<<<<<<< HEAD
 ### `redact-info-log` <span class="version-mark">New in v5.0.0-rc</span>
+=======
+### `redact-info-log` <span class="version-mark">New in v4.0.10</span>
+>>>>>>> 5b116f80... Log redact on TiFlash and PD (4.0) (#4997)
 
 + Controls whether to enable log redaction in the PD log.
 + When you set the configuration value to `true`, user data is redacted in the PD log.

tiflash/tiflash-configuration.md

@@ -165,6 +165,11 @@ delta_index_cache_size = 0
     # cert_path = "/path/to/tiflash-server.pem"
     ## Path of the file that contains X509 key in PEM format.
     # key_path = "/path/to/tiflash-server-key.pem"
+
+    ## New in v4.0.10. This configuration item enables or disables log redaction. If the configuration value
+    ## is set to `true`, all user data in the log will be replaced by `?`.
+    ## Note that you also need to set `security.redact-info-log` for tiflash-learner's logging in tiflash-learner.toml.
+    # redact_info_log = false
 ```
 
 ### Configure the `tiflash-learner.toml` file