Disk Throughput Requirements

The following table describes the disk throughput requirements in OCNADD:

Table 3-6 Disk Throughput Requirements

Avg Size (in Bytes)	Rate	RF (Kafka Replication Factor)	Topic (NF+MAIN)	Consumer Feed	Total Write Throughput (MB/s)	Total Read Throughput (MB/s)	No. of Broker	Per Broker Write Throughput (MB/s)	Per Broker Read Throughput (MB/s)	Total per Broker Throughput (MB/s) with 10% buffer	Total Disk Throughput (MB/s) for the Cluster with 10% Buffer
1941	39000	1	2	1	145	145	3	54	54	108	324
1941	39000	2	2	1	289	289	3	106	106	212	636
3769	39000	1	2	1	281	281	3	104	104	208	624
3769	39000	2	2	1	561	561	3	206	206	412	1236

Note:

• The average size of OCNADD Ingress message captured in the table includes the size of metadata list + header list of original 5G HTTP2 header frame + 5G-SBI-Message.
• For OCNADD 22.0.0, it is recommended to set the Replication Factor (RF) value to 1 with the assumption that the underlying storage provides data redundancy.

The disk throughput calculations are as follows:

Writes: W * RF * T    
Reads: ((RF*T)+C- 1) * W    
Disk Throughput (Write + Read): (W * RF *T) + (L * W)
W -> MB/sec of data that will be written                
RF -> Replication factor                
T   -> No of topics to which data copied. As of now, each message will be copied into two topics.                
C   -> Number of consumer groups, that is the number of readers for each write                
L   -> (RF*T) + C -1

Average Message in Table:

Average Message Size= (a1b1+a2b2+..+a(n)b(n))/(a1+a2+..+a(n))  
a1   -> SCP MPS    
b1   -> SCP message size    
a2   -> NRF MPS    
b2   -> NRF message size    
a(n) -> NF(n) MPS    
b(n) -> NF(n) message size    

Example:

Average message size for row 1 = ((1624*30000)+(3000*9000))/(30000+9000) = 1941 Bytes (approx)

Average message size for row 4 = ((4000*30000)+(3000*9000))/(30000+9000) = 3769 Bytes (approx)

The following table describes the disk throughput for SCP and NRF:

Table 3-7 SCP and NRF Disk Throughput

SCP Message		NRF Message	RF (Kafka Replication Factor)	Topic (NF+MAIN)	Consumer Feed	Total Write Throughput (MB/s)	Total Read Throughput (MB/s)	No.of Broker	Per Broker Write Throughput (MB/s)	Per Broker Read Throughput (MB/s)	Total per Broker Throughput (MB/s) with 10% buffer	Total Disk Throughput (MB/s) for Cluster with 10% Buffer
Avg Size (in Bytes)	Rate	Avg Size (in Bytes)											Rate
1624	30000	3000	9000	1	2	1	145	145	3	54	54	108	324
1624	30000	3000	9000	2	2	1	289	289	3	106	106	212	636
4000	30000	3000	9000	1	2	1	281	281	3	104	104	208	624
4000	30000	3000	9000	2	2	1	561	561	3	206	206	412	1236