How many transactions can be opened?

[sqllyw]

I have this use case:

get_record:

con.startNewTransaction((err, tx) => {

    // fetch
    // resolve the result to caller
    tx.commit( (err) => {})
})

in the webpage, it displays multiple records by calling get_record, that means multiple transactions got opened almost same time, sometimes I got:

while query - error writing data to the connection while query - error reading data ...

is there a limit to how many transactions can be started? if I just use the default transaction, this seems not happening, but there is a desktop app that updates the database, with default transaction, changes will not be shown in the page until this web app got restarted.

or is there a better approach to this scenario?