Serialize calls to bitcoind RPC

tracker/mempool-processor.js

@@ -259,7 +259,10 @@ class MempoolProcessor {
     const unconfirmedTxs = await db.getUnconfirmedTransactions()
 
     if (unconfirmedTxs.length > 0) {
-      await util.parallelCall(unconfirmedTxs, tx => {
+      const unconfirmedTxLists = util.splitList(unconfirmedTxs, 10)
+
+      await util.seriesCall(unconfirmedTxLists, async (txList) => {
+        return await util.parallelCall(txList, tx => {
           try {
             return this.client.getrawtransaction( { txid: tx.txnTxid, verbose: true })
               .then(async rtx => {
@@ -271,7 +274,8 @@ class MempoolProcessor {
                   return db.confirmTransactions([tx.txnTxid], block.blockID)
                 }
               },
-            () => {
+              (e) => {
+                Logger.error(e, 'Tracker : MempoolProcessor.checkUnconfirmed()')
                 // Transaction not in mempool. Update LRU cache and database
                 TransactionsBundle.cache.del(tx.txnTxid)
                 // TODO: Notify clients of orphaned transaction
@@ -282,6 +286,7 @@ class MempoolProcessor {
             Logger.error(e, 'Tracker : MempoolProcessor.checkUnconfirmed()')
           }
         })
+      })
     }
 
     // Logs