Pick of the Week at Nebula Graph - DB-Engines Graph DBMS Ranking Update in September

Steam
2020-09-04

Pick of the Week

Normally the weekly issue covers Nebula Graph Updates and Community Q&As. If something major happens, it will also be covered in the additional Events of the Week section.

Events of the Week

  1. DB-Engines Ranking of Graph DBMS of September

In August, the ranks of the Top 9, even of the Top 20, graph DBMSs in DB-Engines Ranking had only minor changes. Nebula Graph was still ranking at 19th, but earned 0.08 more scores in August.

db-engines ranking of graph dbms in September

  1. Data Migration from JanusGraph to Nebula Graph in 360 Finance

360 Finance, Inc. (NASDAQ: QFIN) has just migrated from JanusGraph to Nebula Graph. They shared the experience with the Nebula Graph community: why and how.

In the Nebula Graph community, Zhou Peng at 360 Finance Inc., a leading digital consumer finance company, shared his experience in data migration from JanusGraph to Nebula Graph. He illustrated how the data migration improved the performance by 20 times with only one-third resources that are for JanusGraph. For more information, visit our forum and communicate with Zhou Peng about his post Data migration from JanusGraph to Nebula Graph.

Nebula Graph Updates

The updates of Nebula in the last week:

• Fixed the bug that may cause a storage crash during the process of vertex deletion in some cases. For more information, check this pull request https://github.com/vesoft-inc/nebula/pull/2335.

• Improved the output of the SHOW HOSTS statement. With the enhancement, the records are returned in order. For more information, check this pull request https://github.com/vesoft-inc/nebula/pull/2334.

output of SHOW HOSTS statement

Community Q&A

The community Q&A topic for the last week is about UUID() errors and the deployment of Nebula Graph server.

About UUID() errors

During the process of vertex insertion, the execute error: Get UUID Failed error may occur when the built-in UUID() function is invoked.

Possible reasons:

  1. The network performance between the graphd service and the storaged service is not good, and an unacceptable I/O latency occurs.

  2. During the deployment, network connections fail between the graphd service and the storaged service.

About deployment of Nebula Graph server

During the deployment of a metad service for Nebula Graph, one node keeps fail.

Server configurations:

• Three 16-core physical servers • Each server has one graphd service, one storaged service, and one metad service

Symptoms:

Of the metad services, two started successfully, but one failed. Here is the log:

I0824 15:32:06.928279 65490 MetaDaemon.cpp:105] Leader has not been elected, sleep 1s
I0824 15:32:07.125378 65536 RaftPart.cpp:1194] [Port: 45501, Space: 0, Part: 0] No one is elected, continue the election
I0824 15:32:07.891225 65533 RaftPart.

Reasons:

The firewalls were enabled for these servers, so the network connection was blocked.

Solution:

Disable the firewalls and allow the ports.

Previous Pick of the Week

  1. Import data from Neo4J or JanusGraph to Nebula Graph
  2. Release of Studio v1.1.0-beta
  3. Performance Testing Report Comparing Nebula Graph with Other Graph DBMSs
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