March 17, 2012, 2:50 pm
I had this problem last week. The /var filesystem was full, but contained few files. This in term seemed to kill cifs and the web interface, though nfs was fine.
Long story short, it’s probably snmpd, there’s a bug in a version of the isilon os (possibly fixed now).
You can use fstat to find abnormally large open files (unfortunately lsof isn’t present, so I couldn’t see a way to locate unlinked files) and the process that has them open. You can then kill -9 snmpd. After that you can restart services as follows:
isi services apache2 disable
Isi services apache2 enable
isi services cifs disable
isi services cifs enable
You may also need to kill off webui/smbd (killall -9 isi_webui_d).
March 17, 2012, 12:05 am
A simple, rough and ready, maxheap implementation. It uses an vector as an implicit complete binary tree:
#include <iostream>
#include <stdlib.h>
#include <vector>
#include <algorithm>
#include <limits.h>
using namespace std;
class Heap {
public:
Heap() {
store.push_back(0);
}
int l_child(int idx) {
return idx*2;
}
int r_child(int idx) {
return (idx*2)+1;
}
int get_parent(int idx) {
return (idx/2);
}
void insert(int val) {
store.push_back(val);
int idx = store.size()-1;
if(idx == 1) return;
// bubble up
for(;store[get_parent(idx)] < store[idx];) {
int t = store[get_parent(idx)];
store[get_parent(idx)] = val;
store[idx] = t;
idx = get_parent(idx);
if(get_parent(idx) == 0) break;
}
}
void dump() {
cout << "DUMPSTART" << endl;
for(size_t n=0;n<store.size();n++) {
cout << store[n] << endl;
}
cout << "DUMPEND" << endl;
}
int pop() {
int r = store[1];
store[1] = store[store.size()-1];
store.pop_back();
bool min=true;
int idx = 1;
for(;min==true;) {
min=false;
int lidx = l_child(idx);
int ridx = r_child(idx);
int lval;
int rval;
if(lidx < store.size()) lval = store[lidx]; else lval = INT_MIN;
if(ridx < store.size()) rval = store[ridx]; else rval = INT_MIN;
if(store[idx] < lval) { min=true; }
if(store[idx] < rval) { min=true; }
if(!min) break;
int t = store[idx];
if(lval > rval) {
store[idx] = store[l_child(idx)];
store[l_child(idx)] = t;
idx = l_child(idx);
} else {
store[idx] = store[r_child(idx)];
store[r_child(idx)] = t;
idx = r_child(idx);
}
}
return r;
}
vector<int> store;
};
int main() {
vector<int> testdata;
for(size_t n=0;n<10;n++) testdata.push_back(rand()%20);
Heap myheap;
for(size_t n=0;n<testdata.size();n++) myheap.insert(testdata[n]);
cout << "popping heap:" << endl;
for(size_t n=0;n<testdata.size();n++) cout << myheap.pop() << endl;
cout << "sorted testdata:" << endl;
sort(testdata.rbegin(),testdata.rend());
for(size_t n=0;n<testdata.size();n++) cout << testdata[n] << endl;
cout << "second test: " << endl;
Heap myheap2;
for(size_t n=0;n<testdata.size();n++) myheap2.insert(testdata[n]);
for(size_t n=0;n<(testdata.size()/2);n++) cout << myheap2.pop() << endl;
myheap2.insert(100);
myheap2.insert(7);
for(size_t n=0;n<(testdata.size()/2)+2;n++) cout << myheap2.pop() << endl;
}
March 15, 2012, 2:17 am
In (not particularly beautiful) C++, both recursive and non-recursive reverse methods:
#include <iostream>
using namespace std;
class ListItem {
public:
ListItem() : next(NULL)
{}
char data[100];
ListItem *next;
void reverse(ListItem *p) {
if(next == NULL) {
next = p;
} else {
next->reverse(this);
next = p;
}
}
};
class LinkedList {
public:
LinkedList() {}
ListItem *start;
ListItem *end;
ListItem *push_back(char *data) {
ListItem *i = new ListItem();
if(end != NULL) { end->next = i; }
else { start = i; }
for(size_t n=0;n<100;n++) {i->data[n] = data[n];}
end = i;
return i;
}
void reverse() {
start->reverse(NULL);
ListItem *temp = end;
end = start;
start = temp;
}
void reverse_nonrec() {
ListItem *last=NULL;
for(ListItem *p=start;p!=NULL;) {
ListItem *next = p->next;
p->next = last;
last = p;
p = next;
}
ListItem *temp = end;
end = start;
start = temp;
}
void dump() {
for(ListItem *p=start;p!=NULL;p=p->next) {
cout << "data: " << p->data << endl;
}
}
~LinkedList() {
ListItem *op = NULL;
for(ListItem *p=start;p!=NULL;p=p->next) {
if(op != NULL) delete op;
op = p;
}
if(op != NULL) delete op;
}
};
int main() {
LinkedList mylist;
char tempdata[100];
for(size_t n=0;n<100;n++) { tempdata[n] = 'A'; }
tempdata[99] = 0;
for(size_t n=0;n<20;n++) {
mylist.push_back(tempdata);
for(size_t n=0;n<99;n++) { tempdata[n]++; }
}
mylist.dump();
mylist.reverse();
cout << "Reversed List" << endl;
mylist.dump();
cout << "Reverse again" << endl;
mylist.reverse_nonrec();
mylist.dump();
}
March 14, 2012, 1:15 am
#include <vector>
#include <iostream>
using namespace std;
void reverse(vector<int> &seq,int n1,int n2) {
for(;(n2-n1)>=1;) {
int temp = seq[n1]; seq[n1] = seq[n2]; seq[n2]=temp;
n1++;
n2--;
}
}
int main() {
int seq_len=4;
vector<int> seq;
for(int n=0;n<seq_len;n++) {seq.push_back(n);}
for(int n=0;n<seq.size();n++) cout << seq[n] << " ";
cout << endl;
for(int n=0;n<seq_len;n++) {
for(bool final=false;final==false;) {
final=true;
int k=0;
for(int n=0;n<(seq.size()-1);n++) {
if(seq[n] < seq[n+1]) {k=n; final=false;}
}
if(!final) {
int l;
for(int n=k+1;n<seq.size();n++) {
if(seq[k] < seq[n]) {
l=n;
}
}
int temp = seq[k]; seq[k] = seq[l]; seq[l] = temp;
reverse(seq,k+1,seq.size()-1);
for(int n=0;n<seq.size();n++) cout << seq[n] << " ";
cout << endl;
}
}
}
}
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