Cache Performance Report

The cache performance report shows the performance of the clients’ caches, the proxy server’s cache, and the direct connections.

Client Cache

A client cache hit occurs when a client performs an up-to-date check on a document and the remote server returns a 304 message telling the client that the document was not modified. An up-to-date check initiated by a client indicates that the client has its own copy of the document in the cache.

For the client’s cache, the report shows:

• Client and proxy cache hits: A client cache hit in which the proxy server and the client both have a copy of the requested document and the remote server is queried for an up-to-date check with respect to the proxy’s copy and the client’s request is then evaluated with respect to the proxy’s copy. The cache performance report shows the number of requests of this type that the proxy serviced and the average amount of time it took to service these requests.

• Proxy shortcut no-check: A client cache hit in which the proxy server and the client both have a copy of the requested document and the proxy server tells the client without checking with the remote server that the document in the client’s cache is up-to-date. The cache performance report shows the number of requests of this type that the proxy serviced and the average time used to service these requests.

• Client cache hits only: A client cache hit in which only the client has a cached copy of the requested document. In this type of request, the proxy server directly tunnels the client’s If-modified-since GET header. The cache performance report shows the number of requests of this type that the proxy serviced and the average time used to service these requests.

• Total client cache hits: the total number of client cache hits and the average amount of time used to service these requests.

Proxy Cache

A proxy cache hit occurs when a client requests a document from a proxy server and the proxy server already has the document in its cache. For the proxy server’s cache hits, the report shows:

• Proxy cache hits with check: A proxy cache hit in which the proxy server queries the remote server for an up-to-date check on the document. The cache performance report shows the number of requests of this type that the proxy serviced and the average time used to service these requests.

• Proxy cache hits without check: A proxy cache hit in which the proxy server does not query the remote server for an up-to-date check on the document. The cache performance report shows the number of requests of this type that the proxy serviced and the average time used to service these requests.

• pure proxy cache hits: A proxy cache hit in which the client does not have a cached copy of the requested document. The cache performance report shows the number of requests of this type that the proxy serviced and the average time used to service these requests.

Proxy Cache Hits Combined

For the proxy cache hits combined, the report shows the total number of hits to the proxy server’s cache and the average amount of time it took to service these requests.

Direct Transactions

Direct transactions are those that go directly from the remote server to the proxy server to the client without any cache hits. For the direct transactions, the report shows:

• Retrieved documents: Documents retrieved directly from the remote server. The cache performance report shows the number of requests of this type that the proxy serviced, the average time it took to service these requests, and the percentage of total transactions.

• Other transactions:Transactions that are returned with a status code other than 200 or 304. The cache performance report shows the number of requests of this type that the proxy serviced and the average time it took to service these requests.

• Total direct traffic: Requests, both failed requests and successfully retrieved documents that went directly from the client to the remote server. The cache performance report shows the number of requests of this type that the proxy serviced, the average time used to service these requests, and the percentage of total transactions.

The following example is a sample cache performance report.

                  
CLIENT CACHE:
- Client & proxy cache hits... 86 reqs [18.0%] 0.21 sec/req- Proxy shortcut 
no-check........ 13 reqs [ 2.7%] 0.00 sec/req- Client cache hits only.....
- TOTAL client cache hits.......... 99 reqs [20.7%] 0.18 sec/req

                  PROXY CACHE:
- Proxy cache hits w/check........ 4 reqs [ 0.8%] 0.50 sec/req- Proxy cache 
hits w/o check.. 10 reqs [ 2.1%] 0.00 sec/req- Pure proxy cache hits...... 
14 reqs [ 2.9%] 0.14 sec/req

                  PROXY CACHE HITS COMBINED:
- TOTAL proxy cache hits....... 113 reqs [23.6%] 0.18 sec/req

                  DIRECT TRANSACTIONS:
- Retrieved documents..313 reqs [65.5%]  0.90 sec/req 2 MB- Other 
transactions.. 52 reqs [10.9%] 7.79 sec/req- TOTAL direct traffic..
365 reqs [76.4%] 1.88 sec/req 2 MB