diff --git a/xdocs/lucene-sandbox/larm/overview.xml b/xdocs/lucene-sandbox/larm/overview.xml index fdd80b24f5e..409a33c46eb 100644 --- a/xdocs/lucene-sandbox/larm/overview.xml +++ b/xdocs/lucene-sandbox/larm/overview.xml @@ -209,16 +209,16 @@

The LARM web crawler is a result of experiences with the errors as mentioned above, connected with a lot of monitoring to get the maximum out - of the given system ressources. It was designed with several different + of the given system resources. It was designed with several different aspects in mind:

@@ -314,7 +314,7 @@ Still, there's a relatively high memory overhead per server and also some overhead per page, especially since a map of already crawled pages is held in memory at this time. Although some of the - in-memory structures are already put on disc, memory consumption is still + in-memory structures are already put on disk, memory consumption is still linear to the number of pages crawled. We have lots of ideas on how to move that out, but since then, as an example with 500 MB RAM, the crawler scales up to some 100.000 files on some 100s of hosts. @@ -574,7 +574,7 @@ that dots "." were not supported in mapped properties indexes. As with the new version (1.5 at the time of this writing) this is supposed to be removed, but I have not tried yet. Therefore, the comma "," was made a - synonymon for dots. Since "," is not allowed in domain names, you can + synonym for dots. Since "," is not allowed in domain names, you can still use (and even mix) them if you want, or if you only have an older BeanUtils version available.

@@ -585,7 +585,7 @@

LARM currently provides a very simple LuceneStorage that allows for - integrating the crawler with Lucene. It's ment to be a working example on + integrating the crawler with Lucene. It's meant to be a working example on how this can be accomplished, not a final implementation. If you like to volunteer on that part, contributions are welcome.

@@ -692,7 +692,7 @@ Probably it is copied through several buffers until it is complete. This will take some CPU time, but mostly it will wait for the next packet to arrive. The network transfer by itself is also affected by a lot of - factors, i.e. the speed of the web server, acknowledgement messages, + factors, i.e. the speed of the web server, acknowledgment messages, resent packages etc. so 100% network utilization will almost never be reached.
  • The document is processed, which will take up the whole CPU. The @@ -747,7 +747,7 @@ this until you have read the standard literature and have made at least 10 mistakes (and solved them!).

    - Multithreading doesn't come without a cost, however. First, there is + Multi-threading doesn't come without a cost, however. First, there is the cost of thread scheduling. I don't have numbers for that in Java, but I suppose that this should not be very expensive. MutExes can affect the whole program a lot . I noticed that they should be avoided like @@ -966,7 +966,7 @@

    In the first implementation the fetcher would simply distribute the incoming URLs to the threads. The thread pool would use a simple queue to - store the remaining tasks. But this can lead to a very "unpolite" + store the remaining tasks. But this can lead to a very "impolite" distribution of the tasks: Since ¾ of the links in a page point to the same server, and all links of a page are added to the message handler at once, groups of successive tasks would all try to access the same server, @@ -1010,7 +1010,7 @@ already resolved host names.

  • the crawler itself was designed to crawl large local networks, and - not the internet. Thus, the number of hosts is very limited.
  • + not the Internet. Thus, the number of hosts is very limited. @@ -1095,9 +1095,9 @@

    - One thing to keep in mind is that the number of URLs transferred to - other nodes should be as large as possible.

    - + One thing to keep in mind is that the transfer of URLs to + other nodes should be done in batches with hundreds or + thousands or more URLs per batch.

    The next thing to be distributed is the storage mechanism. Here, the number of pure crawling nodes and the number of storing (post processing)