- [x] better locking. when lots of requests come in, we seem to be in the way of block updates
- [x] load balance between multiple RPC servers
- [x] support more than just ETH
- [x] option to disable private rpc and send everything to primary
- [x] support websocket clients
- we support websockets for the backends already, but we need them for the frontend too
- [x] health check nodes by block height
- [x] Dockerfile
- [x] docker-compose.yml
- [x] after connecting to a server, check that it gives the expected chainId
- [x] the ethermine rpc is usually fastest. but its in the private tier. since we only allow synced rpcs, we are going to not have an rpc a lot of the time
- [x] if not backends. return a 502 instead of delaying?
- [x] move from warp to axum
- [x] handle websocket disconnect and reconnect
- [x] eth_sendRawTransaction should return the most common result, not the first
- [x] the web3proxyapp object gets cloned for every call. why do we need any arcs inside that? shouldn't they be able to connect to the app's? can we just use static lifetimes
- [x] when sending with private relays, brownie's tx.wait can think the transaction was dropped. smarter retry on eth_getTransactionByHash and eth_getTransactionReceipt (maybe only if we sent the transaction ourselves)
- [x] if web3 proxy gets an http error back, retry another node
- [x] endpoint for health checks. if no synced servers, give a 502 error
- originally, no processing was done to params; they were just serde_json::RawValue. this is probably fastest, but we need to look for "latest" and count elements, so we have to use serde_json::Value
- [x] subscription id should be per connection, not global
- [x] when under load, i'm seeing "http interval lagging!". sometimes it happens when not loaded.
- we were skipping our delay interval when block hash wasn't changed. so if a block was ever slow, the http provider would get the same hash twice and then would try eth_getBlockByNumber a ton of times
- [x] inspect any jsonrpc errors. if its something like "header not found" or "block with id $x not found" retry on another node (and add a negative score to that server)
- this error seems to happen when we use load balanced backend rpcs like pokt and ankr
- we can improve this by only publishing the synced connections once a threshold of total available soft and hard limits is passed. how can we do this without hammering redis? at least its only once per block per server
- [x] instead of tracking `pending_synced_connections`, have a mapping of where all connections are individually. then each change, re-check for consensus.
- [x] if the eth_call (or similar) params include a block, we can cache for that
- [x] when block subscribers receive blocks, store them in a block_map
- [x] eth_blockNumber without a backend request
- [x] if we send a transaction to private rpcs and then people query it on public rpcs things, some interfaces might think the transaction is dropped (i saw this happen in a brownie script of mine). how should we handle this?
- [x] send getTransaction rpc requests to the private rpc tier
- [cancelled] eth_getBlockByNumber and similar calls served from the block map
- will need all Block<TxHash>**and** Block<TransactionReceipt> in caches or fetched efficiently
- so maybe we don't want this. we can just use the general request cache for these. they will only require 1 request and it means requests won't get in the way as much on writes as new blocks arrive.
- [ ] synced connections swap threshold should come from config
- if there are bad forks, we need to think about this more. keep backfilling until there is a common block, or just error? if the common block is old, i think we should error rather than serve data. that's kind of "downtime" but really its on the chain and not us. think about this more
- [ ] have a "backup" tier that is only used when the primary tier has no servers or is many blocks behind
- we don't want the backup tier taking over with the head block if they happen to be fast at that (but overall low/expensive rps). only if the primary tier has fallen behind or gone entirely offline should we go to third parties
- [ ] until this is done, an alternative is for infra to have a "failover" script that changes the configs to include a bunch of third party servers manually.
- [ ] right now we send too many getTransaction queries to the private rpc tier and i are being rate limited by some of them. change to be serial and weight by hard/soft limit.
- [ ] Got warning: "WARN subscribe_new_heads:send_block: web3_proxy::connection: unable to get block from https://rpc.ethermine.org: Deserialization Error: expected value at line 1 column 1. Response: error code: 1015". this is cloudflare rate limiting on fetching a block, but this is a private rpc. why is there a block subscription?
- [ ] basic transaction firewall
- this is part done, but we need to pick a database schema to check
- [ ] cli for creating and editing api keys
- [ ] cli for blocking malicious contracts with the firewall
- deposits history (currency, amounts, transaction id)
- number of requests used (so we can calculate average spending over a month, burn rate for a user etc, something like "Your balance will be depleted in xx days)
- the email address of a user if he opted in to get contacted via email
- all the success/retry/fail counts and latencies (but that may better come from somewhere else)
- checks a transaction to see if it modifies a user's balance. records results in a sql database
- we will have our own event subscriber watching for "deposit" events, but sometimes events get missed and users might incorrectly "transfer" the tokens directly to an address instead of using the dapp
- [ ] use https://github.com/ledgerwatch/interfaces to talk to erigon directly instead of through erigon's rpcdaemon (possible example code which uses ledgerwatch/interfaces: https://github.com/akula-bft/akula/tree/master)
- [ ] flashbots protect fast mode or not? probably fast matches most user's needs, but no reverts is nice.
- [ ] https://docs.flashbots.net/flashbots-auction/searchers/advanced/rpc-endpoint#authentication maybe have per-user keys. or pass their header on if its set
- [ ] if archive servers are added to the rotation while they are still syncing, they might get requests too soon. keep archive servers out of the configs until they are done syncing. full nodes should be fine to add to the configs even while syncing, though its a wasted connection
- [ ] archive check works well for local servers, but public nodes (especially on other chains) seem to give unreliable results. likely because of load balancers. maybe have a "max block data limit"
- [ ] https://crates.io/crates/reqwest-middleware easy retry with exponential back off
- Though I think we want retries that go to other backends instead
- [ ] Some of the pub things should probably be "pub(crate)"
- [ ] Maybe storing pending txs on receipt in a dashmap is wrong. We want to store in a timer_heap (or similar) when we actually send. This way there's no lock contention until the race is over.
- [ ] Support "safe" block height. It's planned for eth2 but we can kind of do it now but just doing head block num-3
- [ ] Archive check on BSC gave “archive” when it isn’t. and FTM gave 90k for all servers even though they should be archive
