NDB – Forced node shutdown completed. Caused by error 2341: ‘Internal program error (failed ndbrequire)

recently while working on MySQL cluster 7.3.5, we came across this error

Forced node shutdown completed. Caused by error 2341: 'Internal program error (failed ndbrequire)(Internal error, programming error or missing error message, please report a bug). Temporary error, restart node'.

The management nodes would start up but

the data nodes would complete phase 1 & shutdown, some times at phase 2 and some times at phase 5.

The error one would see in the trace file would be as follows:

Status: Temporary error, restart node
Message: Internal program error (failed ndbrequire) (Internal error, programming error or missing error message, please report a bug)
Error: 2341
Error data: CREATE_TABLE_REF
Error object: NDBCNTR (Line: 2493) 0x00000003
Program: ndbd

How did we resolve it ?

First, few of our data nodes had an incorrect connect-string

Second, we had pre-assigned NodeGroups for the data nodes in the config.ini, and had started our node groups with serial number 1.

[ndbd]

NodeGroupt=1

HostName=10.95.139.92

[ndbd]

NodeGroupt=2

HostName=10.95.139.92

Apparently, NDB likes to start up with serial number 0 onwards, so we changed  to

[ndbd]

NodeGroupt= 0

HostName=10.95.139.92

[ndbd]

NodeGroupt= 1

HostName=10.95.139.92

and walaa our cluster started up.

Thanks to Frank, for giving the work around (here).

Mobile Hack Day

its been a long time since i had a post on M*A*S*H and its nice to blog again.

Well yesterday, on August 7,  we had our HACK day and the theme was MOBILE.  I have participated in all flipkart hack days and i must tell you , they are simply awesome.

Last time the team ( Chetna/Anirudh/ Abhijat  & I )  went out to make Chota Minority Report (link here) and we had an awesome time. we won the Laziest but Effective Hack Award.

This time we set out to make something Different.  Since the Theme was MOBILE, we intended to do just that 🙂

How about making the MOBILE(noun) truly MOBILE (verb) !!!

Chetna & Anirdudh worked on the android app & Abhijat & I worked on the hardware.

We came up with 2 hacks.

The first is    Bhaag Mobile Bhaag  –  the mobile becomes mobile.

 

THE  HACK  MOBILE

 

as per the theme , we made the mobile truly mobile 🙂

We made a mobile app (which we can control remotely) and this app flashes light.

once light hits the censor, the vehicle (which we programmed) starts moving. once light stops, the vehicle stops.

A video of mobility below 🙂

 

The second is called  “App Suicide”

A simple idea – with the motto –  “Customer First“,  the app cares for the customer and it is willing to save on battery for the customer.

All in all , a great hack day and we had fun.

Team:  Chetna/Anirudh/ Abhijat / Vishnu

PS: we work in the data platform on project Bigfoot @ flipkart