Duplicate or oversized orders
Duplicate or oversized orders almost always mean two copiers are running. How to tell a real duplicate from a scale-in, and how to fix it.
Updated
Seeing two orders where you expected one, or a follower that copied at double size? First rule out the leader genuinely trading twice. A true duplicate, the same fill copied over again, comes from one thing: two copiers running against the same accounts at once.
Some apparent duplicates are real trades
Before assuming a fault, check whether the leader actually placed more than one order. A few normal cases produce more follower orders than you might expect:
- Partial fills. A single leader order that fills in several pieces can copy across as more than one follower order, sized so the pieces add up to the right total.
- Scaling in. If the leader adds to a position with separate orders, each one is a real fill and each copies.
- Re-entries. The leader exits and gets back in. Two round trips on the leader are two round trips on the followers.
These are the copier doing its job. Risk limits and lockouts still apply throughout: a follower that hits its daily loss limit or profit target, or that you have locked, stops copying no matter how many times the leader trades.
Why one copier can't double a fill
Inside a single running OmenSyncer, every leader execution is handled exactly once. The moment a fill arrives it is checked against the executions already seen, and a repeat is dropped before any order goes out. That protection lives in memory inside one process. It works perfectly for the copier it runs in, but it has no way of knowing about a second copier running somewhere else.
What causes true duplicates
Two separate copiers, each connected to the same leader and followers, both see the fill and both fan out orders. Neither knows the other exists, so each account gets the trade twice. The usual setups:
- The desktop app and the cloud copier are both live for the same accounts.
- Two desktop instances are open at once, on one machine or two, both signed in and connected.
- A copier was left running on an old machine or a VPS and forgotten after you moved to a new one.
The same thing explains an order that looks oversized. It isn't one double-size order; it is two normal-size orders landing so close together they read as one.
How to check
- List every place you've set OmenSyncer up: the desktop app on each computer, plus the web dashboard if you use the cloud copier.
- For each one, check whether its connections are on and pointed at the same leader and followers.
- If more than one is live against the same accounts, that is your duplicate source.
A quick tell: if the duplicate lands on every follower, a second copier is almost certainly running. A one-off on a single account is more likely a broker retry.
How to fix it
Pick one copier to be the live one and shut the others down, either by quitting the app or by switching that copier's connections off so it places no orders. Run a single copier per set of accounts and duplicates stop immediately.
Setting up cleanly from the start avoids this. See Best practices for running one copier per account set.