# Casper 2.0 Upgrade: Sidecar Service Fails to Connect to Node on Testnet (Continuous Restarts)

**URL:** <https://forum.casper.network/t/casper-2-0-upgrade-sidecar-service-fails-to-connect-to-node-on-testnet-continuous-restarts/1393>\
**Category:** Node Support\
**Created:** [March 17, 2025, 9:22am UTC](https://forum.casper.network/t/casper-2-0-upgrade-sidecar-service-fails-to-connect-to-node-on-testnet-continuous-restarts/1393 "2025-03-17T09:22:47Z")\
**Posts on this page:** 3\
**Page:** 1

<div class="post-metadata">

**Author:** ![Marc\_CSPR](https://yyz1.discourse-cdn.com/flex035/user_avatar/forum.casper.network/marc_cspr/32/31_2.png) [@Marc\_CSPR](https://forum.casper.network/u/Marc_CSPR)\
**Post date:** [March 17, 2025, 9:22am UTC](https://forum.casper.network/t/casper-2-0-upgrade-sidecar-service-fails-to-connect-to-node-on-testnet-continuous-restarts/1393/1 "2025-03-17T09:22:47Z")

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## 1. Issue Summary

- **Title of the Issue:** Casper Sidecar Fails to Connect to Node (Testnet TTL Node)
- **Description:** The `casper-sidecar` service restarts continuously due to connection timeouts to the Casper node on `127.0.0.1:7779`. The node is a Testnet TTL node (v1.5.8), and UFW is disabled. The sidecar fails with `Error initializing component 'rpc_api_server'`.

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## 2. Node Information

- **Node Type:** TTL Node (Testnet)
- **Casper Node Version:** 1.5.8
- **Network:** Testnet

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## 3. Error Details

- **Logs and Error Messages:**

Mar 17 08:56:54 Ubuntu-2004-focal-64-minimal systemd[1]: Started Casper Sidecar.  
Mar 17 08:56:54 Ubuntu-2004-focal-64-minimal casper-sidecar[1035633]: 2025-03-17T07:56:54.650107Z WARN casper\_rpc\_sidecar::node\_client: failed to connect to node 127.0.0.1:7779, waiting 1000ms before retryi\>  
Mar 17 08:56:55 Ubuntu-2004-focal-64-minimal casper-sidecar[1035633]: 2025-03-17T07:56:55.651517Z WARN casper\_rpc\_sidecar::node\_client: failed to connect to node 127.0.0.1:7779, waiting 2000ms before retryi\>  
Mar 17 08:56:57 Ubuntu-2004-focal-64-minimal casper-sidecar[1035633]: 2025-03-17T07:56:57.652881Z WARN casper\_rpc\_sidecar::node\_client: failed to connect to node 127.0.0.1:7779, waiting 4000ms before retryi\>  
Mar 17 08:57:01 Ubuntu-2004-focal-64-minimal casper-sidecar[1035633]: 2025-03-17T07:57:01.654173Z WARN casper\_rpc\_sidecar::node\_client: failed to connect to node 127.0.0.1:7779, waiting 8000ms before retryi\>  
Mar 17 08:57:09 Ubuntu-2004-focal-64-minimal casper-sidecar[1035633]: 2025-03-17T07:57:09.655720Z WARN casper\_rpc\_sidecar::node\_client: failed to connect to node 127.0.0.1:7779, waiting 16000ms before retry\>  
Mar 17 08:57:24 Ubuntu-2004-focal-64-minimal casper-sidecar[1035633]: 2025-03-17T07:57:24.650402Z ERROR casper\_sidecar::run: The server has exited with an error: Error initializing component ‘rpc\_api\_server’\>  
Mar 17 08:57:24 Ubuntu-2004-focal-64-minimal casper-sidecar[1035633]: Error: Error initializing component ‘rpc\_api\_server’: Failed to start component rpc\_api\_server in 30 [s]  
Mar 17 08:57:24 Ubuntu-2004-focal-64-minimal systemd[1]: casper-sidecar.service: Main process exited, code=exited, status=1/FAILURE  
Mar 17 08:57:24 Ubuntu-2004-focal-64-minimal systemd[1]: casper-sidecar.service: Failed with result ‘exit-code’.  
Mar 17 08:57:25 Ubuntu-2004-focal-64-minimal systemd[1]: casper-sidecar.service: Scheduled restart job, restart counter is at 626.  
Mar 17 08:57:25 Ubuntu-2004-focal-64-minimal systemd[1]: Stopped Casper Sidecar.  
Mar 17 08:57:25 Ubuntu-2004-focal-64-minimal systemd[1]: Started Casper Sidecar.

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<div class="post-metadata">

**Author:** ![Jiuhong](https://avatars.discourse-cdn.com/v4/letter/j/b9bd4f/32.png) [@Jiuhong](https://forum.casper.network/u/Jiuhong)\
**Post date:** [March 17, 2025, 10:05am UTC](https://forum.casper.network/t/casper-2-0-upgrade-sidecar-service-fails-to-connect-to-node-on-testnet-continuous-restarts/1393/2 "2025-03-17T10:05:23Z")

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That is normal for the testnet and mainnet at the moment since the sidecar will be running normally only when Casper-2.0 is upgraded.

Currently the casper-sidecar’s log should show

```auto
Mar 17 09:59:31 ca casper-sidecar[79474]: 2025-03-17T09:59:31.833406Z WARN casper_rpc_sidecar::node_client: failed to connect to node 127.0.0.1:7779, waiting 2000ms before retrying; err=Connection refused (os error 111)

```

since the the binary port 7779 is for Casper-2.0 only.  
Once the testnet/mainnet is upgraded to Casper-2.0 the sidecar should be working.

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<div class="post-metadata">

**Author:** ![Marc\_CSPR](https://yyz1.discourse-cdn.com/flex035/user_avatar/forum.casper.network/marc_cspr/32/31_2.png) [@Marc\_CSPR](https://forum.casper.network/u/Marc_CSPR)\
**Post date:** [March 17, 2025, 10:08am UTC](https://forum.casper.network/t/casper-2-0-upgrade-sidecar-service-fails-to-connect-to-node-on-testnet-continuous-restarts/1393/3 "2025-03-17T10:08:21Z")

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Ok.  
Thanks for the clarification.