## Description
Setup with Besu, LH BC & LH VC. VC seems to lose connection to… BC.
I tried:
- restarting all services
- resyncing BC with checkpoint sync
## Version
`v4.0.2-rc.0`
## Present Behaviour
BC logs don't show anything unusual.
Errors in VC:
```
Apr 30 16:05:47.878 INFO Successfully published attestations type: unaggregated, slot: 6337226, committee_index: 54, head_block: 0xebdcf96f86d61001585454dd2b4a3086ae4e38f6da7ea25de61729a9bf8aedd8, validator_indices: [], count: 0, service: attestation
Apr 30 16:05:47.879 DEBG Request to beacon node failed error: "No aggregate available for AttestationData { slot: Slot(6337226), index: 54, beacon_block_root: 0xebdcf96f86d61001585454dd2b4a3086ae4e38f6da7ea25de61729a9bf8aedd8, source: Checkpoint { epoch: Epoch(198037), root: 0x42e925532fce00fc81beca5da88319a82d038a5ab0e2671981e9f12abc776871 }, target: Checkpoint { epoch: Epoch(198038), root: 0xf505cdac4b7379cc260c6b58b30531cee18dd05ec968e380f60241f7f81a35a8 } }", node: http://stereum-ac4c61eb-6976-9de3-b6f1-48c29a215355:5052/
Apr 30 16:05:47.879 CRIT Error during attestation routine slot: 6337226, committee_index: 54, error: "Some endpoints failed, num_failed: 1 http://stereum-ac4c61eb-6976-9de3-b6f1-48c29a215355:5052/ => RequestFailed(\"No aggregate available for AttestationData { slot: Slot(6337226), index: 54, beacon_block_root: 0xebdcf96f86d61001585454dd2b4a3086ae4e38f6da7ea25de61729a9bf8aedd8, source: Checkpoint { epoch: Epoch(198037), root: 0x42e925532fce00fc81beca5da88319a82d038a5ab0e2671981e9f12abc776871 }, target: Checkpoint { epoch: Epoch(198038), root: 0xf505cdac4b7379cc260c6b58b30531cee18dd05ec968e380f60241f7f81a35a8 } }\")", service: attestation
Apr 30 16:05:47.881 INFO Successfully published attestations type: unaggregated, slot: 6337226, committee_index: 32, head_block: 0xebdcf96f86d61001585454dd2b4a3086ae4e38f6da7ea25de61729a9bf8aedd8, validator_indices: [430031], count: 1, service: attestation
Apr 30 16:05:47.882 INFO Connected to beacon node endpoint: http://stereum-ac4c61eb-6976-9de3-b6f1-48c29a215355:5052/, version: Lighthouse/v4.0.2-rc.0-35d8c98/x86_64-linux
Apr 30 16:05:48.584 INFO Successfully published attestations type: unaggregated, slot: 6337226, committee_index: 49, head_block: 0xebdcf96f86d61001585454dd2b4a3086ae4e38f6da7ea25de61729a9bf8aedd8, validator_indices: [432238], count: 1, service: attestation
Apr 30 16:05:48.585 INFO Successfully published attestations type: unaggregated, slot: 6337226, committee_index: 20, head_block: 0xebdcf96f86d61001585454dd2b4a3086ae4e38f6da7ea25de61729a9bf8aedd8, validator_indices: [431688], count: 1, service: attestation
Apr 30 16:05:51.001 DEBG No local validators in current sync committee, slot: 6337227, service: sync_committee
Apr 30 16:05:51.001 DEBG Fetching subscription duties current_slot: 6337227, duty_slot: 6337227, service: sync_committee
Apr 30 16:05:51.001 DEBG No sync subscriptions to send slot: 6337227, service: sync_committee
Apr 30 16:05:51.338 INFO Successfully published attestations type: unaggregated, slot: 6337227, committee_index: 32, head_block: 0x0a49f36fe421e2f855ef0449dd22203d055a5c00b21478098c454f86df25d99d, validator_indices: [432237], count: 1, service: attestation
Apr 30 16:05:51.447 INFO Successfully published attestations type: unaggregated, slot: 6337227, committee_index: 43, head_block: 0x0a49f36fe421e2f855ef0449dd22203d055a5c00b21478098c454f86df25d99d, validator_indices: [433094], count: 1, service: attestation
Apr 30 16:05:51.448 INFO Successfully published attestations type: unaggregated, slot: 6337227, committee_index: 52, head_block: 0x0a49f36fe421e2f855ef0449dd22203d055a5c00b21478098c454f86df25d99d, validator_indices: [436430], count: 1, service: attestation
Apr 30 16:05:51.518 INFO Successfully published attestations type: unaggregated, slot: 6337227, committee_index: 15, head_block: 0x0a49f36fe421e2f855ef0449dd22203d055a5c00b21478098c454f86df25d99d, validator_indices: [431902], count: 1, service: attestation
Apr 30 16:05:51.519 INFO Successfully published attestations type: unaggregated, slot: 6337227, committee_index: 25, head_block: 0x0a49f36fe421e2f855ef0449dd22203d055a5c00b21478098c454f86df25d99d, validator_indices: [436008], count: 1, service: attestation
Apr 30 16:05:51.566 INFO Successfully published attestations type: unaggregated, slot: 6337227, committee_index: 45, head_block: 0x0a49f36fe421e2f855ef0449dd22203d055a5c00b21478098c454f86df25d99d, validator_indices: [418892], count: 1, service: attestation
Apr 30 16:05:51.569 INFO Successfully published attestations type: unaggregated, slot: 6337227, committee_index: 20, head_block: 0x0a49f36fe421e2f855ef0449dd22203d055a5c00b21478098c454f86df25d99d, validator_indices: [432869], count: 1, service: attestation
Apr 30 16:05:53.001 INFO Connected to beacon node(s) synced: 1, available: 1, total: 1, service: notifier
Apr 30 16:05:53.001 INFO All validators active slot: 6337227, epoch: 198038, total_validators: 500, active_validators: 500, current_epoch_proposers: 0, service: notifier
Apr 30 16:05:53.374 INFO Successfully published attestations type: unaggregated, slot: 6337227, committee_index: 5, head_block: 0x0a49f36fe421e2f855ef0449dd22203d055a5c00b21478098c454f86df25d99d, validator_indices: [433089], count: 1, service: attestation
Apr 30 16:05:53.374 INFO Successfully published attestations type: unaggregated, slot: 6337227, committee_index: 36, head_block: 0x0a49f36fe421e2f855ef0449dd22203d055a5c00b21478098c454f86df25d99d, validator_indices: [433090], count: 1, service: attestation
Apr 30 16:05:55.006 INFO Successfully published attestation type: aggregated, slot: 6337227, committee_index: 52, head_block: 0x0a49f36fe421e2f855ef0449dd22203d055a5c00b21478098c454f86df25d99d, signatures: 1, aggregator: 436430, service: attestation
Apr 30 16:05:55.006 INFO Successfully published attestation type: aggregated, slot: 6337227, committee_index: 5, head_block: 0x0a49f36fe421e2f855ef0449dd22203d055a5c00b21478098c454f86df25d99d, signatures: 1, aggregator: 433089, service: attestation
Apr 30 16:05:55.006 INFO Successfully published attestation type: aggregated, slot: 6337227, committee_index: 36, head_block: 0x0a49f36fe421e2f855ef0449dd22203d055a5c00b21478098c454f86df25d99d, signatures: 1, aggregator: 433090, service: attestation
Apr 30 16:05:55.007 INFO Successfully published attestation type: aggregated, slot: 6337227, committee_index: 25, head_block: 0x0a49f36fe421e2f855ef0449dd22203d055a5c00b21478098c454f86df25d99d, signatures: 1, aggregator: 436008, service: attestation
Apr 30 16:05:55.788 DEBG Measured BN latency latency: 0, node: http://stereum-ac4c61eb-6976-9de3-b6f1-48c29a215355:5052/
Apr 30 16:05:56.388 CRIT Not signing slashable attestation error: SQLPoolError("timed out waiting for connection"), attestation: AttestationData { slot: Slot(6337227), index: 31, beacon_block_root: 0x0a49f36fe421e2f855ef0449dd22203d055a5c00b21478098c454f86df25d99d, source: Checkpoint { epoch: Epoch(198037), root: 0x42e925532fce00fc81beca5da88319a82d038a5ab0e2671981e9f12abc776871 }, target: Checkpoint { epoch: Epoch(198038), root: 0xf505cdac4b7379cc260c6b58b30531cee18dd05ec968e380f60241f7f81a35a8 } }
Apr 30 16:05:56.388 CRIT Failed to sign attestation slot: 6337227, committee_index: 31, validator: 0x94787d7167e21db1e629e29153c48cd53035bdf2cb2d34bcf0428702267717cc300af9eb5fd981ca109798db8718c6b8, error: Slashable(SQLPoolError("timed out waiting for connection")), service: attestation
Apr 30 16:05:56.391 INFO Successfully published attestations type: unaggregated, slot: 6337227, committee_index: 31, head_block: 0x0a49f36fe421e2f855ef0449dd22203d055a5c00b21478098c454f86df25d99d, validator_indices: [436422], count: 1, service: attestation
Apr 30 16:05:56.391 INFO Successfully published attestations type: unaggregated, slot: 6337227, committee_index: 27, head_block: 0x0a49f36fe421e2f855ef0449dd22203d055a5c00b21478098c454f86df25d99d, validator_indices: [411179], count: 1, service: attestation
Apr 30 16:05:56.963 INFO Successfully published attestations type: unaggregated, slot: 6337227, committee_index: 12, head_block: 0x0a49f36fe421e2f855ef0449dd22203d055a5c00b21478098c454f86df25d99d, validator_indices: [433005], count: 1, service: attestation
Apr 30 16:05:56.965 INFO Successfully published attestations type: unaggregated, slot: 6337227, committee_index: 62, head_block: 0x0a49f36fe421e2f855ef0449dd22203d055a5c00b21478098c454f86df25d99d, validator_indices: [435326, 414154], count: 2, service: attestation
Apr 30 16:05:59.016 DEBG Computed attestation selection proofs time_taken_ms: 15, lookahead_slot: 6337236, batch_size: 21, service: duties
```
BC logs:
```
Apr 30 16:05:00.163 INFO New block received root: 0xc0c51a21376570ff84a3d9cfb02a68e10aa9138084b16d9657e5faa5f96cf53b, slot: 6337223
Apr 30 16:05:05.000 INFO Downloading historical blocks est_time: 2 days 2 hrs, speed: 34.67 slots/sec, distance: 6319489 slots (125 weeks 2 days), service: slot_notifier
Apr 30 16:05:05.000 INFO Synced slot: 6337223, block: 0xc0c5…f53b, epoch: 198038, finalized_epoch: 198036, finalized_root: 0x2c27…c055, exec_hash: 0x8959…8c47 (verified), peers: 59, service: slot_notifier
Apr 30 16:05:05.000 WARN Syncing deposit contract block cache est_blocks_remaining: initializing deposits, service: slot_notifier
Apr 30 16:05:12.488 INFO New block received root: 0x6fb51c5d7f917b61d1f0e0f1445a0431096f0f09a77bc040f3a7c55d0d9f9a8a, slot: 6337224
Apr 30 16:05:17.000 INFO Synced slot: 6337224, block: 0x6fb5…9a8a, epoch: 198038, finalized_epoch: 198036, finalized_root: 0x2c27…c055, exec_hash: 0xaaf9…e50f (verified), peers: 60, service: slot_notifier
Apr 30 16:05:17.000 WARN Syncing deposit contract block cache est_blocks_remaining: initializing deposits, service: slot_notifier
Apr 30 16:05:24.303 INFO New block received root: 0x39294f957aae4539512e6793bedf30eeb35319f7a18717198c52eb5bcebfc9e6, slot: 6337225
Apr 30 16:05:29.000 INFO Synced slot: 6337225, block: 0x3929…c9e6, epoch: 198038, finalized_epoch: 198036, finalized_root: 0x2c27…c055, exec_hash: 0x4543…8f6a (verified), peers: 61, service: slot_notifier
Apr 30 16:05:29.000 WARN Syncing deposit contract block cache est_blocks_remaining: initializing deposits, service: slot_notifier
Apr 30 16:05:36.724 INFO New block received root: 0xebdcf96f86d61001585454dd2b4a3086ae4e38f6da7ea25de61729a9bf8aedd8, slot: 6337226
Apr 30 16:05:41.000 INFO Synced slot: 6337226, block: 0xebdc…edd8, epoch: 198038, finalized_epoch: 198036, finalized_root: 0x2c27…c055, exec_hash: 0xda67…e3ba (verified), peers: 62, service: slot_notifier
Apr 30 16:05:41.000 WARN Syncing deposit contract block cache est_blocks_remaining: initializing deposits, service: slot_notifier
Apr 30 16:05:48.293 INFO New block received root: 0x0a49f36fe421e2f855ef0449dd22203d055a5c00b21478098c454f86df25d99d, slot: 6337227
Apr 30 16:05:53.000 INFO Synced slot: 6337227, block: 0x0a49…d99d, epoch: 198038, finalized_epoch: 198036, finalized_root: 0x2c27…c055, exec_hash: 0x6c36…d739 (verified), peers: 62, service: slot_notifier
Apr 30 16:05:53.000 WARN Syncing deposit contract block cache est_blocks_remaining: initializing deposits, service: slot_notifier
Apr 30 16:06:00.632 INFO New block received root: 0xe6a78949a9d0cd8bb0c5aeb4bd020227f7c284bb04344e07586a76d83939e059, slot: 6337228
Apr 30 16:06:05.000 INFO Downloading historical blocks est_time: 1 day 11 hrs, speed: 49.34 slots/sec, distance: 6315969 slots (125 weeks 2 days), service: slot_notifier
Apr 30 16:06:05.000 INFO Synced slot: 6337228, block: 0xe6a7…e059, epoch: 198038, finalized_epoch: 198036, finalized_root: 0x2c27…c055, exec_hash: 0x5d34…181c (verified), peers: 62, service: slot_notifier
Apr 30 16:06:05.000 WARN Syncing deposit contract block cache est_blocks_remaining: initializing deposits, service: slot_notifier
Apr 30 16:06:12.984 INFO New block received root: 0xd30b68f3d81b7a773ccca0ea25d9638f1d6b27dcc40abb992d6ab04b26da18c8, slot: 6337229
Apr 30 16:06:17.000 INFO Synced slot: 6337229, block: 0xd30b…18c8, epoch: 198038, finalized_epoch: 198036, finalized_root: 0x2c27…c055, exec_hash: 0x27fc…7ac2 (verified), peers: 63, service: slot_notifier
Apr 30 16:06:17.000 WARN Syncing deposit contract block cache est_blocks_remaining: initializing deposits, service: slot_notifier
Apr 30 16:06:24.074 INFO New block received root: 0x6fd092d4186832871d6ded6f0bf9337d5a9791405aeb6ba735cf2f20937870c3, slot: 6337230
Apr 30 16:06:29.001 INFO Synced slot: 6337230, block: 0x6fd0…70c3, epoch: 198038, finalized_epoch: 198036, finalized_root: 0x2c27…c055, exec_hash: 0x854c…32db (verified), peers: 63, service: slot_notifier
```
## Expected Behaviour
VC not losing connection to BC every slot.
## Steps to resolve
Unknown.