Saying lengthy du’aa’ during Taraaweeh prayer

What is correct it to make it neither too long nor too short.
Making it so long that it causes hardship to people is not allowed. When the
Prophet (peace and blessings of Allaah be upon him) heard that Mu’aadh
ibn Jabal was making the prayers too long for his people, he spoke to him
angrily in a manner that he had never used when advising someone and said to
Mu’aadh: “O Mu’aadh, are you putting people off?” (al-Bukhaari, al-Adab,
6106; Muslim, al-Salaah, 465). What the imam should do is to adhere
to the Sunnah.

 Undoubtedly making the du’aa’ too long causes hardship to
the people and exhausts them, especially those who are weak. Some people may
have work to do, or they may not want to finish before the imam but it is
difficult for them to stay with the imam. So we advise our brother imams to
follow a moderate course, and to omit the du’aa’ sometimes so that the
people will not think that the du’aa’ is obligatory.