Database Reference
In-Depth Information
Bywayofaninitial comparison,lookattheresultsdetailed in
table 10.2
,showingthetime
in milliseconds for embedded and server modes (with nodes per second in parentheses)
taken to create one million new user nodes with a
name
property. Each new node was cre-
ated in its own transaction (TX) using the raw Java API in embedded mode versus the raw
REST API of the server mode.
Table 10.2. The initial results of embedded versus server mode performance when creating new nodes
Scenario
Description
Embedded
Server
1 1 TX per node (1,000,000 × 1) 168,815 ms (5,952 nodes/s) 2,380,140 ms (420 nodes/s)
* Run on a MacBook Pro with 16 GB of RAM and 1 TB SSD (with FileVault FS encryption turned on). The Neo4j
server was run on the same local machine that the unit test was run on, and the unit test made use of the neo4j-rest-
graphdb REST client library detailed earlier.
On the face of it, these numbers don't make for very good reading, even for the embedded
mode. Three odd minutes to create 1 million nodes? Don't despair just yet; this example
was designed to prove a point. We could argue that the question should never be a simple
case of which one is faster. Rather, given a scenario, what can be done to get the best per-
formance, andisthisperformance levelacceptable. Afewadjustments tothewayinwhich
the operations are performed can have a drastic effect on performance.
Table 10.3
shows how the performance gets a lot better when you start to make better use
of transactions (native transactions in embedded mode, and batches for server mode). This
simple change has a big effect on the original numbers: up to 10 times faster for the em-
bedded mode and 16 times faster for the server mode using batches.
Table 10.3. Extended results of embedded versus server mode performance when creating new nodes
Scenario
Description
Embedded
Server
1
1 TX per node (1,000,000 × 1) 168,815 ms (5,952 nodes/s)
2,380,140 ms (420 nodes/s)
1 TX for all nodes (1 ×
1,000,000)
2
25,654 ms (40,000 nodes/s)
Took too long, hung
3
Batched TXs (20 × 50,000)
16,081 ms (62,500 nodes/s)
148,357 ms (6756 nodes/s)
Wheneveryou'representedwithperformancenumbers,makesureyouunderstandhowthe
performance test was put together and what factors are in play—or not. To lay all of our
cards on the table,
listings 10.9
and
10.10
show the code used to perform these comparis-
ons.
