update tidb.net and asktug links (#22496) (#22770)

Author: ti-chi-bot

explore-htap.md

@@ -108,7 +108,7 @@ If any issue occurs during using TiDB, refer to the following documents:
 - [TiDB cluster troubleshooting guide](/troubleshoot-tidb-cluster.md)
 - [Troubleshoot a TiFlash Cluster](/tiflash/troubleshoot-tiflash.md)
 
-You are also welcome to create [GitHub Issues](https://github.com/pingcap/tiflash/issues) or submit your questions on [AskTUG](https://asktug.com/).
+You are also welcome to create [GitHub Issues](https://github.com/pingcap/tiflash/issues) or ask the community on [Discord](https://discord.gg/DQZ2dy3cuc?utm_source=doc) or [Slack](https://slack.tidb.io/invite?team=tidb-community&channel=everyone&ref=pingcap-docs).
 
 ## What's next
 

faq/manage-cluster-faq.md

@@ -109,7 +109,7 @@ You can scale TiDB as your business grows.
 
 ### If Percolator uses distributed locks and the crash client keeps the lock, will the lock not be released?
 
-For more details, see [Percolator and TiDB Transaction Algorithm](https://tidb.net/blog/f537be2c) in Chinese.
+For more details, see [Percolator and TiDB Transaction Algorithm](https://pingkai.cn/tidbcommunity/blog/f537be2c) in Chinese.
 
 ### Why does TiDB use gRPC instead of Thrift? Is it because Google uses it?
 

tidb-troubleshooting-map.md

@@ -401,7 +401,7 @@ Check the specific cause for busy by viewing the monitor **Grafana** -> **TiKV**
 
     - The database related passwords in all the DM configuration files should be encrypted by `dmctl`. If a database password is empty, it is unnecessary to encrypt the password. Cleartext passwords can be used since v1.0.6.
     - During DM operation, the user of the upstream and downstream databases must have the corresponding read and write privileges. Data Migration also [prechecks the corresponding privileges](/dm/dm-precheck.md) automatically while starting the data replication task.
-    - To deploy different versions of DM-worker/DM-master/dmctl in a DM cluster, see the [case study on AskTUG](https://asktug.com/t/dm1-0-0-ga-access-denied-for-user/1049/5) in Chinese.
+    - To deploy different versions of DM-worker/DM-master/dmctl in a DM cluster, see the [case study on AskTUG](https://pingkai.cn/tidbcommunity/forum/t/topic/1049/5) in Chinese.
 
 - 6.1.3 A replication task is interrupted with the `driver: bad connection` error returned.