Match Engine Order Placement query

[blockchain-app12]

I start all the servers in the Architecture as mentioned,

• Zookeeper
• Kafka
• Go Engine
• Redis
• MySQL with BIN-LOG Config

I added pairs into the match engine, then I placed orders in the match engine.
In the scenario, I have faced sometimes order placement issue when matching, which can be seen in the MySQL status as - "new".
whenever the placed order as "new" that orders couldn't match or Engine couldn't considered that order to matching.Only the engine considered the open orders for matching.
In this type of scenario, I empty the records in all the servers then re-inject the pairs and orders in to the engine.
So kindly let me know, what are all the scenario's that placing orders considered as status as - "new".