retry on not found

Readme.md

@@ -36,5 +36,7 @@ To configure the service for your specific environment, you'll need to set the f
 `NETWORK_PASSPHRASE` - Soroban passphrase\
 `LIQUIDATOR_ADDRESS` - liquidator's account address\
 `LIQUIDATOR_SECRET` - liquidator's secret key\
+`GET_TRANSACTIONS_RETRY` - number of retries to get transaction for particular ledgers\
+`GET_TRANSACTIONS_DELAY_MS` - delay before retrying
 ## License
 This project is licensed under the MIT License - see the LICENSE file for details.

src/sync.ts

@@ -1,35 +1,49 @@
 import { CONTRACT_CREATION_LEDGER, HORIZON_URL, POOL_ID } from "./configuration";
-import { Horizon, SorobanRpc, humanizeEvents, xdr } from "@stellar/stellar-sdk";
+import { Horizon, NotFoundError, SorobanRpc, humanizeEvents, xdr } from "@stellar/stellar-sdk";
 import { insertBorrowers, readLastSyncedLedger, updateLastSyncedLedger } from "./infrastructure/db/domain";
+import { delay } from "./infrastructure/soroban/contracts";
 
 export const populateDbWithBorrowers = async (rpc: SorobanRpc.Server) => {
     let lastLedger = (await rpc.getLatestLedger()).sequence;
     const lastSyncedLedger = await readLastSyncedLedger();
 
     if (lastLedger > lastSyncedLedger) {
         const horizon = new Horizon.Server(HORIZON_URL);
+        let retries = parseInt(process.env.GET_TRANSACTIONS_RETRY, 10);
         let currentLedger = lastSyncedLedger === 0 ? parseInt(CONTRACT_CREATION_LEDGER.toString()) : lastSyncedLedger + 1;
 
         console.log(`Sync from: ${currentLedger} to: ${lastLedger}`);
 
         while (lastLedger > currentLedger) {
-            const transactions = await horizon.transactions().forLedger(currentLedger).call();
-
-            for (const tx of transactions.records) {
-                const xdrMeta = xdr.TransactionMeta.fromXDR(tx.result_meta_xdr, "base64").v3().sorobanMeta();
-
-                if (!xdrMeta || !xdrMeta.events())
+            try {
+                const transactions = await horizon.transactions().forLedger(currentLedger).call();
+                for (const tx of transactions.records) {
+                    const xdrMeta = xdr.TransactionMeta.fromXDR(tx.result_meta_xdr, "base64").v3().sorobanMeta();
+
+                    if (!xdrMeta || !xdrMeta.events())
+                        continue;
+
+                    const events = humanizeEvents(xdrMeta.events())
+                        .filter(e => e.contractId === POOL_ID && e.topics[0] === 'borrow');
+                    const borrower = events.map(e => e.topics[1]);
+
+                    await insertBorrowers(borrower);
+                }
+
+                await updateLastSyncedLedger(currentLedger);
+            } catch (e) {
+                if (e instanceof NotFoundError) {
+                    retries -= 1;
+                    if (retries === 0) {
+                        throw e;
+                    }
+                    await delay(process.env.GET_TRANSACTIONS_DELAY_MS);
                     continue;
-
-                const events = humanizeEvents(xdrMeta.events())
-                    .filter(e => e.contractId === POOL_ID && e.topics[0] === 'borrow');
-                const borrower = events.map(e => e.topics[1]);
-
-                await insertBorrowers(borrower);
+                } else {
+                    throw e;
+                }
             }
 
-            await updateLastSyncedLedger(currentLedger);
-
             currentLedger += 1;
             lastLedger = (await rpc.getLatestLedger()).sequence;
         }